diff --git a/src/3d/PyVoxelGrid.cpp b/src/3d/PyVoxelGrid.cpp
new file mode 100644
index 0000000..3325a73
--- /dev/null
+++ b/src/3d/PyVoxelGrid.cpp
@@ -0,0 +1,598 @@
+// PyVoxelGrid.cpp - Python bindings for VoxelGrid implementation
+// Part of McRogueFace 3D Extension - Milestone 9
+
+#include "PyVoxelGrid.h"
+#include "../McRFPy_API.h"
+#include "../PyColor.h"
+#include <sstream>
+
+// =============================================================================
+// Python type interface
+// =============================================================================
+
+PyObject* PyVoxelGrid::pynew(PyTypeObject* type, PyObject* args, PyObject* kwds) {
+    PyVoxelGridObject* self = (PyVoxelGridObject*)type->tp_alloc(type, 0);
+    if (self) {
+        self->data = nullptr;  // Will be initialized in init
+        self->weakreflist = nullptr;
+    }
+    return (PyObject*)self;
+}
+
+int PyVoxelGrid::init(PyVoxelGridObject* self, PyObject* args, PyObject* kwds) {
+    static const char* kwlist[] = {"size", "cell_size", nullptr};
+
+    PyObject* size_obj = nullptr;
+    float cell_size = 1.0f;
+
+    if (!PyArg_ParseTupleAndKeywords(args, kwds, "O|f", const_cast<char**>(kwlist),
+                                      &size_obj, &cell_size)) {
+        return -1;
+    }
+
+    // Parse size tuple
+    if (!PyTuple_Check(size_obj) && !PyList_Check(size_obj)) {
+        PyErr_SetString(PyExc_TypeError, "size must be a tuple or list of 3 integers");
+        return -1;
+    }
+
+    if (PySequence_Size(size_obj) != 3) {
+        PyErr_SetString(PyExc_ValueError, "size must have exactly 3 elements (width, height, depth)");
+        return -1;
+    }
+
+    int width = 0, height = 0, depth = 0;
+
+    PyObject* w_obj = PySequence_GetItem(size_obj, 0);
+    PyObject* h_obj = PySequence_GetItem(size_obj, 1);
+    PyObject* d_obj = PySequence_GetItem(size_obj, 2);
+
+    bool valid = true;
+    if (PyLong_Check(w_obj)) width = (int)PyLong_AsLong(w_obj); else valid = false;
+    if (PyLong_Check(h_obj)) height = (int)PyLong_AsLong(h_obj); else valid = false;
+    if (PyLong_Check(d_obj)) depth = (int)PyLong_AsLong(d_obj); else valid = false;
+
+    Py_DECREF(w_obj);
+    Py_DECREF(h_obj);
+    Py_DECREF(d_obj);
+
+    if (!valid) {
+        PyErr_SetString(PyExc_TypeError, "size elements must be integers");
+        return -1;
+    }
+
+    if (width <= 0 || height <= 0 || depth <= 0) {
+        PyErr_SetString(PyExc_ValueError, "size dimensions must be positive");
+        return -1;
+    }
+
+    if (cell_size <= 0.0f) {
+        PyErr_SetString(PyExc_ValueError, "cell_size must be positive");
+        return -1;
+    }
+
+    // Create the VoxelGrid
+    try {
+        self->data = std::make_shared<mcrf::VoxelGrid>(width, height, depth, cell_size);
+    } catch (const std::exception& e) {
+        PyErr_SetString(PyExc_RuntimeError, e.what());
+        return -1;
+    }
+
+    return 0;
+}
+
+void PyVoxelGrid::dealloc(PyVoxelGridObject* self) {
+    PyObject_GC_UnTrack(self);
+    if (self->weakreflist != nullptr) {
+        PyObject_ClearWeakRefs((PyObject*)self);
+    }
+    self->data.reset();
+    Py_TYPE(self)->tp_free((PyObject*)self);
+}
+
+PyObject* PyVoxelGrid::repr(PyObject* obj) {
+    PyVoxelGridObject* self = (PyVoxelGridObject*)obj;
+    if (!self->data) {
+        return PyUnicode_FromString("<VoxelGrid (uninitialized)>");
+    }
+
+    std::ostringstream oss;
+    oss << "<VoxelGrid " << self->data->width() << "x"
+        << self->data->height() << "x" << self->data->depth()
+        << " cells=" << self->data->totalVoxels()
+        << " materials=" << self->data->materialCount()
+        << " non_air=" << self->data->countNonAir() << ">";
+    return PyUnicode_FromString(oss.str().c_str());
+}
+
+// =============================================================================
+// Properties - dimensions (read-only)
+// =============================================================================
+
+PyObject* PyVoxelGrid::get_size(PyVoxelGridObject* self, void* closure) {
+    if (!self->data) {
+        PyErr_SetString(PyExc_RuntimeError, "VoxelGrid not initialized");
+        return nullptr;
+    }
+    return Py_BuildValue("(iii)", self->data->width(), self->data->height(), self->data->depth());
+}
+
+PyObject* PyVoxelGrid::get_width(PyVoxelGridObject* self, void* closure) {
+    if (!self->data) {
+        PyErr_SetString(PyExc_RuntimeError, "VoxelGrid not initialized");
+        return nullptr;
+    }
+    return PyLong_FromLong(self->data->width());
+}
+
+PyObject* PyVoxelGrid::get_height(PyVoxelGridObject* self, void* closure) {
+    if (!self->data) {
+        PyErr_SetString(PyExc_RuntimeError, "VoxelGrid not initialized");
+        return nullptr;
+    }
+    return PyLong_FromLong(self->data->height());
+}
+
+PyObject* PyVoxelGrid::get_depth(PyVoxelGridObject* self, void* closure) {
+    if (!self->data) {
+        PyErr_SetString(PyExc_RuntimeError, "VoxelGrid not initialized");
+        return nullptr;
+    }
+    return PyLong_FromLong(self->data->depth());
+}
+
+PyObject* PyVoxelGrid::get_cell_size(PyVoxelGridObject* self, void* closure) {
+    if (!self->data) {
+        PyErr_SetString(PyExc_RuntimeError, "VoxelGrid not initialized");
+        return nullptr;
+    }
+    return PyFloat_FromDouble(self->data->cellSize());
+}
+
+PyObject* PyVoxelGrid::get_material_count(PyVoxelGridObject* self, void* closure) {
+    if (!self->data) {
+        PyErr_SetString(PyExc_RuntimeError, "VoxelGrid not initialized");
+        return nullptr;
+    }
+    return PyLong_FromSize_t(self->data->materialCount());
+}
+
+// =============================================================================
+// Properties - transform (read-write)
+// =============================================================================
+
+PyObject* PyVoxelGrid::get_offset(PyVoxelGridObject* self, void* closure) {
+    if (!self->data) {
+        PyErr_SetString(PyExc_RuntimeError, "VoxelGrid not initialized");
+        return nullptr;
+    }
+    mcrf::vec3 offset = self->data->getOffset();
+    return Py_BuildValue("(fff)", offset.x, offset.y, offset.z);
+}
+
+int PyVoxelGrid::set_offset(PyVoxelGridObject* self, PyObject* value, void* closure) {
+    if (!self->data) {
+        PyErr_SetString(PyExc_RuntimeError, "VoxelGrid not initialized");
+        return -1;
+    }
+
+    if (!PyTuple_Check(value) && !PyList_Check(value)) {
+        PyErr_SetString(PyExc_TypeError, "offset must be a tuple or list of 3 floats");
+        return -1;
+    }
+
+    if (PySequence_Size(value) != 3) {
+        PyErr_SetString(PyExc_ValueError, "offset must have exactly 3 elements (x, y, z)");
+        return -1;
+    }
+
+    float x = 0, y = 0, z = 0;
+    PyObject* x_obj = PySequence_GetItem(value, 0);
+    PyObject* y_obj = PySequence_GetItem(value, 1);
+    PyObject* z_obj = PySequence_GetItem(value, 2);
+
+    bool valid = true;
+    if (PyNumber_Check(x_obj)) x = (float)PyFloat_AsDouble(PyNumber_Float(x_obj)); else valid = false;
+    if (PyNumber_Check(y_obj)) y = (float)PyFloat_AsDouble(PyNumber_Float(y_obj)); else valid = false;
+    if (PyNumber_Check(z_obj)) z = (float)PyFloat_AsDouble(PyNumber_Float(z_obj)); else valid = false;
+
+    Py_DECREF(x_obj);
+    Py_DECREF(y_obj);
+    Py_DECREF(z_obj);
+
+    if (!valid) {
+        PyErr_SetString(PyExc_TypeError, "offset elements must be numbers");
+        return -1;
+    }
+
+    self->data->setOffset(x, y, z);
+    return 0;
+}
+
+PyObject* PyVoxelGrid::get_rotation(PyVoxelGridObject* self, void* closure) {
+    if (!self->data) {
+        PyErr_SetString(PyExc_RuntimeError, "VoxelGrid not initialized");
+        return nullptr;
+    }
+    return PyFloat_FromDouble(self->data->getRotation());
+}
+
+int PyVoxelGrid::set_rotation(PyVoxelGridObject* self, PyObject* value, void* closure) {
+    if (!self->data) {
+        PyErr_SetString(PyExc_RuntimeError, "VoxelGrid not initialized");
+        return -1;
+    }
+
+    if (!PyNumber_Check(value)) {
+        PyErr_SetString(PyExc_TypeError, "rotation must be a number");
+        return -1;
+    }
+
+    float rotation = (float)PyFloat_AsDouble(PyNumber_Float(value));
+    self->data->setRotation(rotation);
+    return 0;
+}
+
+// =============================================================================
+// Voxel access methods
+// =============================================================================
+
+PyObject* PyVoxelGrid::get(PyVoxelGridObject* self, PyObject* args) {
+    if (!self->data) {
+        PyErr_SetString(PyExc_RuntimeError, "VoxelGrid not initialized");
+        return nullptr;
+    }
+
+    int x, y, z;
+    if (!PyArg_ParseTuple(args, "iii", &x, &y, &z)) {
+        return nullptr;
+    }
+
+    // Bounds check with warning (returns 0 for out-of-bounds, like C++ API)
+    if (!self->data->isValid(x, y, z)) {
+        // Return 0 (air) for out-of-bounds, matching C++ behavior
+        return PyLong_FromLong(0);
+    }
+
+    return PyLong_FromLong(self->data->get(x, y, z));
+}
+
+PyObject* PyVoxelGrid::set(PyVoxelGridObject* self, PyObject* args) {
+    if (!self->data) {
+        PyErr_SetString(PyExc_RuntimeError, "VoxelGrid not initialized");
+        return nullptr;
+    }
+
+    int x, y, z, material;
+    if (!PyArg_ParseTuple(args, "iiii", &x, &y, &z, &material)) {
+        return nullptr;
+    }
+
+    if (material < 0 || material > 255) {
+        PyErr_SetString(PyExc_ValueError, "material must be 0-255");
+        return nullptr;
+    }
+
+    // Bounds check - silently ignore out-of-bounds, like C++ API
+    self->data->set(x, y, z, static_cast<uint8_t>(material));
+    Py_RETURN_NONE;
+}
+
+// =============================================================================
+// Material methods
+// =============================================================================
+
+PyObject* PyVoxelGrid::add_material(PyVoxelGridObject* self, PyObject* args, PyObject* kwds) {
+    if (!self->data) {
+        PyErr_SetString(PyExc_RuntimeError, "VoxelGrid not initialized");
+        return nullptr;
+    }
+
+    static const char* kwlist[] = {"name", "color", "sprite_index", "transparent", "path_cost", nullptr};
+
+    const char* name = nullptr;
+    PyObject* color_obj = nullptr;
+    int sprite_index = -1;
+    int transparent = 0;  // Python bool maps to int
+    float path_cost = 1.0f;
+
+    if (!PyArg_ParseTupleAndKeywords(args, kwds, "s|Oipf", const_cast<char**>(kwlist),
+                                      &name, &color_obj, &sprite_index, &transparent, &path_cost)) {
+        return nullptr;
+    }
+
+    // Default color is white
+    sf::Color color = sf::Color::White;
+
+    // Parse color if provided
+    if (color_obj && color_obj != Py_None) {
+        color = PyColor::fromPy(color_obj);
+        if (PyErr_Occurred()) {
+            return nullptr;
+        }
+    }
+
+    try {
+        uint8_t id = self->data->addMaterial(name, color, sprite_index, transparent != 0, path_cost);
+        return PyLong_FromLong(id);
+    } catch (const std::exception& e) {
+        PyErr_SetString(PyExc_RuntimeError, e.what());
+        return nullptr;
+    }
+}
+
+PyObject* PyVoxelGrid::get_material(PyVoxelGridObject* self, PyObject* args) {
+    if (!self->data) {
+        PyErr_SetString(PyExc_RuntimeError, "VoxelGrid not initialized");
+        return nullptr;
+    }
+
+    int id;
+    if (!PyArg_ParseTuple(args, "i", &id)) {
+        return nullptr;
+    }
+
+    if (id < 0 || id > 255) {
+        PyErr_SetString(PyExc_ValueError, "material id must be 0-255");
+        return nullptr;
+    }
+
+    const mcrf::VoxelMaterial& mat = self->data->getMaterial(static_cast<uint8_t>(id));
+
+    // Create color object
+    PyObject* color_type = PyObject_GetAttrString(McRFPy_API::mcrf_module, "Color");
+    if (!color_type) {
+        return nullptr;
+    }
+
+    PyObject* color_obj = PyObject_Call(color_type,
+        Py_BuildValue("(iiii)", mat.color.r, mat.color.g, mat.color.b, mat.color.a),
+        nullptr);
+    Py_DECREF(color_type);
+
+    if (!color_obj) {
+        return nullptr;
+    }
+
+    // Build result dict
+    PyObject* result = Py_BuildValue("{s:s, s:N, s:i, s:O, s:f}",
+        "name", mat.name.c_str(),
+        "color", color_obj,
+        "sprite_index", mat.spriteIndex,
+        "transparent", mat.transparent ? Py_True : Py_False,
+        "path_cost", mat.pathCost);
+
+    return result;
+}
+
+// =============================================================================
+// Bulk operations
+// =============================================================================
+
+PyObject* PyVoxelGrid::fill(PyVoxelGridObject* self, PyObject* args) {
+    if (!self->data) {
+        PyErr_SetString(PyExc_RuntimeError, "VoxelGrid not initialized");
+        return nullptr;
+    }
+
+    int material;
+    if (!PyArg_ParseTuple(args, "i", &material)) {
+        return nullptr;
+    }
+
+    if (material < 0 || material > 255) {
+        PyErr_SetString(PyExc_ValueError, "material must be 0-255");
+        return nullptr;
+    }
+
+    self->data->fill(static_cast<uint8_t>(material));
+    Py_RETURN_NONE;
+}
+
+PyObject* PyVoxelGrid::clear(PyVoxelGridObject* self, PyObject* Py_UNUSED(args)) {
+    if (!self->data) {
+        PyErr_SetString(PyExc_RuntimeError, "VoxelGrid not initialized");
+        return nullptr;
+    }
+
+    self->data->clear();
+    Py_RETURN_NONE;
+}
+
+PyObject* PyVoxelGrid::fill_box(PyVoxelGridObject* self, PyObject* args) {
+    if (!self->data) {
+        PyErr_SetString(PyExc_RuntimeError, "VoxelGrid not initialized");
+        return nullptr;
+    }
+
+    PyObject* min_obj = nullptr;
+    PyObject* max_obj = nullptr;
+    int material;
+
+    if (!PyArg_ParseTuple(args, "OOi", &min_obj, &max_obj, &material)) {
+        return nullptr;
+    }
+
+    if (material < 0 || material > 255) {
+        PyErr_SetString(PyExc_ValueError, "material must be 0-255");
+        return nullptr;
+    }
+
+    // Parse min tuple (x0, y0, z0)
+    if (!PyTuple_Check(min_obj) && !PyList_Check(min_obj)) {
+        PyErr_SetString(PyExc_TypeError, "min_coord must be a tuple or list of 3 integers");
+        return nullptr;
+    }
+    if (PySequence_Size(min_obj) != 3) {
+        PyErr_SetString(PyExc_ValueError, "min_coord must have exactly 3 elements");
+        return nullptr;
+    }
+
+    // Parse max tuple (x1, y1, z1)
+    if (!PyTuple_Check(max_obj) && !PyList_Check(max_obj)) {
+        PyErr_SetString(PyExc_TypeError, "max_coord must be a tuple or list of 3 integers");
+        return nullptr;
+    }
+    if (PySequence_Size(max_obj) != 3) {
+        PyErr_SetString(PyExc_ValueError, "max_coord must have exactly 3 elements");
+        return nullptr;
+    }
+
+    int x0, y0, z0, x1, y1, z1;
+    PyObject* items[6];
+
+    items[0] = PySequence_GetItem(min_obj, 0);
+    items[1] = PySequence_GetItem(min_obj, 1);
+    items[2] = PySequence_GetItem(min_obj, 2);
+    items[3] = PySequence_GetItem(max_obj, 0);
+    items[4] = PySequence_GetItem(max_obj, 1);
+    items[5] = PySequence_GetItem(max_obj, 2);
+
+    bool valid = true;
+    if (PyLong_Check(items[0])) x0 = (int)PyLong_AsLong(items[0]); else valid = false;
+    if (PyLong_Check(items[1])) y0 = (int)PyLong_AsLong(items[1]); else valid = false;
+    if (PyLong_Check(items[2])) z0 = (int)PyLong_AsLong(items[2]); else valid = false;
+    if (PyLong_Check(items[3])) x1 = (int)PyLong_AsLong(items[3]); else valid = false;
+    if (PyLong_Check(items[4])) y1 = (int)PyLong_AsLong(items[4]); else valid = false;
+    if (PyLong_Check(items[5])) z1 = (int)PyLong_AsLong(items[5]); else valid = false;
+
+    for (int i = 0; i < 6; i++) Py_DECREF(items[i]);
+
+    if (!valid) {
+        PyErr_SetString(PyExc_TypeError, "coordinate elements must be integers");
+        return nullptr;
+    }
+
+    self->data->fillBox(x0, y0, z0, x1, y1, z1, static_cast<uint8_t>(material));
+    Py_RETURN_NONE;
+}
+
+// =============================================================================
+// Mesh caching methods (Milestone 10)
+// =============================================================================
+
+PyObject* PyVoxelGrid::get_vertex_count(PyVoxelGridObject* self, void* closure) {
+    if (!self->data) {
+        PyErr_SetString(PyExc_RuntimeError, "VoxelGrid not initialized");
+        return nullptr;
+    }
+    return PyLong_FromSize_t(self->data->vertexCount());
+}
+
+PyObject* PyVoxelGrid::rebuild_mesh(PyVoxelGridObject* self, PyObject* Py_UNUSED(args)) {
+    if (!self->data) {
+        PyErr_SetString(PyExc_RuntimeError, "VoxelGrid not initialized");
+        return nullptr;
+    }
+
+    self->data->rebuildMesh();
+    Py_RETURN_NONE;
+}
+
+// =============================================================================
+// Statistics
+// =============================================================================
+
+PyObject* PyVoxelGrid::count_non_air(PyVoxelGridObject* self, PyObject* Py_UNUSED(args)) {
+    if (!self->data) {
+        PyErr_SetString(PyExc_RuntimeError, "VoxelGrid not initialized");
+        return nullptr;
+    }
+
+    return PyLong_FromSize_t(self->data->countNonAir());
+}
+
+PyObject* PyVoxelGrid::count_material(PyVoxelGridObject* self, PyObject* args) {
+    if (!self->data) {
+        PyErr_SetString(PyExc_RuntimeError, "VoxelGrid not initialized");
+        return nullptr;
+    }
+
+    int material;
+    if (!PyArg_ParseTuple(args, "i", &material)) {
+        return nullptr;
+    }
+
+    if (material < 0 || material > 255) {
+        PyErr_SetString(PyExc_ValueError, "material must be 0-255");
+        return nullptr;
+    }
+
+    return PyLong_FromSize_t(self->data->countMaterial(static_cast<uint8_t>(material)));
+}
+
+// =============================================================================
+// Method definitions
+// =============================================================================
+
+PyMethodDef PyVoxelGrid::methods[] = {
+    {"get", (PyCFunction)get, METH_VARARGS,
+     "get(x, y, z) -> int\n\n"
+     "Get the material ID at integer coordinates.\n\n"
+     "Returns 0 (air) for out-of-bounds coordinates."},
+    {"set", (PyCFunction)set, METH_VARARGS,
+     "set(x, y, z, material) -> None\n\n"
+     "Set the material ID at integer coordinates.\n\n"
+     "Out-of-bounds coordinates are silently ignored."},
+    {"add_material", (PyCFunction)add_material, METH_VARARGS | METH_KEYWORDS,
+     "add_material(name, color=Color(255,255,255), sprite_index=-1, transparent=False, path_cost=1.0) -> int\n\n"
+     "Add a new material to the palette. Returns the material ID (1-indexed).\n\n"
+     "Material 0 is always air (implicit, never stored in palette).\n"
+     "Maximum 255 materials can be added."},
+    {"get_material", (PyCFunction)get_material, METH_VARARGS,
+     "get_material(id) -> dict\n\n"
+     "Get material properties by ID.\n\n"
+     "Returns dict with keys: name, color, sprite_index, transparent, path_cost.\n"
+     "ID 0 returns the implicit air material."},
+    {"fill", (PyCFunction)fill, METH_VARARGS,
+     "fill(material) -> None\n\n"
+     "Fill the entire grid with the specified material ID."},
+    {"fill_box", (PyCFunction)fill_box, METH_VARARGS,
+     "fill_box(min_coord, max_coord, material) -> None\n\n"
+     "Fill a rectangular region with the specified material.\n\n"
+     "Args:\n"
+     "    min_coord: (x0, y0, z0) - minimum corner (inclusive)\n"
+     "    max_coord: (x1, y1, z1) - maximum corner (inclusive)\n"
+     "    material: material ID (0-255)\n\n"
+     "Coordinates are clamped to grid bounds."},
+    {"clear", (PyCFunction)clear, METH_NOARGS,
+     "clear() -> None\n\n"
+     "Clear the grid (fill with air, material 0)."},
+    {"rebuild_mesh", (PyCFunction)rebuild_mesh, METH_NOARGS,
+     "rebuild_mesh() -> None\n\n"
+     "Force immediate mesh rebuild for rendering."},
+    {"count_non_air", (PyCFunction)count_non_air, METH_NOARGS,
+     "count_non_air() -> int\n\n"
+     "Count the number of non-air voxels in the grid."},
+    {"count_material", (PyCFunction)count_material, METH_VARARGS,
+     "count_material(material) -> int\n\n"
+     "Count the number of voxels with the specified material ID."},
+    {nullptr}  // Sentinel
+};
+
+// =============================================================================
+// Property definitions
+// =============================================================================
+
+PyGetSetDef PyVoxelGrid::getsetters[] = {
+    {"size", (getter)get_size, nullptr,
+     "Dimensions (width, height, depth) of the grid. Read-only.", nullptr},
+    {"width", (getter)get_width, nullptr,
+     "Grid width (X dimension). Read-only.", nullptr},
+    {"height", (getter)get_height, nullptr,
+     "Grid height (Y dimension). Read-only.", nullptr},
+    {"depth", (getter)get_depth, nullptr,
+     "Grid depth (Z dimension). Read-only.", nullptr},
+    {"cell_size", (getter)get_cell_size, nullptr,
+     "World units per voxel. Read-only.", nullptr},
+    {"material_count", (getter)get_material_count, nullptr,
+     "Number of materials in the palette. Read-only.", nullptr},
+    {"vertex_count", (getter)get_vertex_count, nullptr,
+     "Number of vertices after mesh generation. Read-only.", nullptr},
+    {"offset", (getter)get_offset, (setter)set_offset,
+     "World-space position (x, y, z) of the grid origin.", nullptr},
+    {"rotation", (getter)get_rotation, (setter)set_rotation,
+     "Y-axis rotation in degrees.", nullptr},
+    {nullptr}  // Sentinel
+};
diff --git a/src/3d/PyVoxelGrid.h b/src/3d/PyVoxelGrid.h
new file mode 100644
index 0000000..92eb13b
--- /dev/null
+++ b/src/3d/PyVoxelGrid.h
@@ -0,0 +1,125 @@
+// PyVoxelGrid.h - Python bindings for VoxelGrid
+// Part of McRogueFace 3D Extension - Milestone 9
+#pragma once
+
+#include "../Common.h"
+#include "Python.h"
+#include "VoxelGrid.h"
+#include <memory>
+
+// Forward declaration
+class PyVoxelGrid;
+
+// =============================================================================
+// Python object structure
+// =============================================================================
+
+typedef struct PyVoxelGridObject {
+    PyObject_HEAD
+    std::shared_ptr<mcrf::VoxelGrid> data;
+    PyObject* weakreflist;
+} PyVoxelGridObject;
+
+// =============================================================================
+// Python binding class
+// =============================================================================
+
+class PyVoxelGrid {
+public:
+    // Python type interface
+    static PyObject* pynew(PyTypeObject* type, PyObject* args, PyObject* kwds);
+    static int init(PyVoxelGridObject* self, PyObject* args, PyObject* kwds);
+    static void dealloc(PyVoxelGridObject* self);
+    static PyObject* repr(PyObject* obj);
+
+    // Properties - dimensions (read-only)
+    static PyObject* get_size(PyVoxelGridObject* self, void* closure);
+    static PyObject* get_width(PyVoxelGridObject* self, void* closure);
+    static PyObject* get_height(PyVoxelGridObject* self, void* closure);
+    static PyObject* get_depth(PyVoxelGridObject* self, void* closure);
+    static PyObject* get_cell_size(PyVoxelGridObject* self, void* closure);
+    static PyObject* get_material_count(PyVoxelGridObject* self, void* closure);
+
+    // Properties - transform (read-write)
+    static PyObject* get_offset(PyVoxelGridObject* self, void* closure);
+    static int set_offset(PyVoxelGridObject* self, PyObject* value, void* closure);
+    static PyObject* get_rotation(PyVoxelGridObject* self, void* closure);
+    static int set_rotation(PyVoxelGridObject* self, PyObject* value, void* closure);
+
+    // Voxel access methods
+    static PyObject* get(PyVoxelGridObject* self, PyObject* args);
+    static PyObject* set(PyVoxelGridObject* self, PyObject* args);
+
+    // Material methods
+    static PyObject* add_material(PyVoxelGridObject* self, PyObject* args, PyObject* kwds);
+    static PyObject* get_material(PyVoxelGridObject* self, PyObject* args);
+
+    // Bulk operations
+    static PyObject* fill(PyVoxelGridObject* self, PyObject* args);
+    static PyObject* fill_box(PyVoxelGridObject* self, PyObject* args);
+    static PyObject* clear(PyVoxelGridObject* self, PyObject* Py_UNUSED(args));
+
+    // Mesh caching (Milestone 10)
+    static PyObject* get_vertex_count(PyVoxelGridObject* self, void* closure);
+    static PyObject* rebuild_mesh(PyVoxelGridObject* self, PyObject* Py_UNUSED(args));
+
+    // Statistics
+    static PyObject* count_non_air(PyVoxelGridObject* self, PyObject* Py_UNUSED(args));
+    static PyObject* count_material(PyVoxelGridObject* self, PyObject* args);
+
+    // Type registration
+    static PyMethodDef methods[];
+    static PyGetSetDef getsetters[];
+};
+
+// =============================================================================
+// Python type definition
+// =============================================================================
+
+namespace mcrfpydef {
+
+inline PyTypeObject PyVoxelGridType = {
+    .ob_base = {.ob_base = {.ob_refcnt = 1, .ob_type = NULL}, .ob_size = 0},
+    .tp_name = "mcrfpy.VoxelGrid",
+    .tp_basicsize = sizeof(PyVoxelGridObject),
+    .tp_itemsize = 0,
+    .tp_dealloc = (destructor)PyVoxelGrid::dealloc,
+    .tp_repr = PyVoxelGrid::repr,
+    .tp_flags = Py_TPFLAGS_DEFAULT | Py_TPFLAGS_BASETYPE | Py_TPFLAGS_HAVE_GC,
+    .tp_doc = PyDoc_STR(
+        "VoxelGrid(size: tuple[int, int, int], cell_size: float = 1.0)\n\n"
+        "A dense 3D grid of voxel material IDs with a material palette.\n\n"
+        "VoxelGrids provide volumetric storage for 3D structures like buildings,\n"
+        "caves, and dungeon walls. Each cell stores a uint8 material ID (0-255),\n"
+        "where 0 is always air.\n\n"
+        "Args:\n"
+        "    size: (width, height, depth) dimensions. Immutable after creation.\n"
+        "    cell_size: World units per voxel. Default 1.0.\n\n"
+        "Properties:\n"
+        "    size (tuple, read-only): Grid dimensions as (width, height, depth)\n"
+        "    width, height, depth (int, read-only): Individual dimensions\n"
+        "    cell_size (float, read-only): World units per voxel\n"
+        "    offset (tuple): World-space position (x, y, z)\n"
+        "    rotation (float): Y-axis rotation in degrees\n"
+        "    material_count (int, read-only): Number of defined materials\n\n"
+        "Example:\n"
+        "    voxels = mcrfpy.VoxelGrid(size=(16, 8, 16), cell_size=1.0)\n"
+        "    stone = voxels.add_material('stone', color=mcrfpy.Color(128, 128, 128))\n"
+        "    voxels.set(5, 0, 5, stone)\n"
+        "    assert voxels.get(5, 0, 5) == stone\n"
+        "    print(f'Non-air voxels: {voxels.count_non_air()}')"
+    ),
+    .tp_traverse = [](PyObject* self, visitproc visit, void* arg) -> int {
+        return 0;
+    },
+    .tp_clear = [](PyObject* self) -> int {
+        return 0;
+    },
+    .tp_weaklistoffset = offsetof(PyVoxelGridObject, weakreflist),
+    .tp_methods = nullptr,  // Set before PyType_Ready
+    .tp_getset = nullptr,   // Set before PyType_Ready
+    .tp_init = (initproc)PyVoxelGrid::init,
+    .tp_new = PyVoxelGrid::pynew,
+};
+
+} // namespace mcrfpydef
diff --git a/src/3d/Viewport3D.cpp b/src/3d/Viewport3D.cpp
index 1997e08..5d1f392 100644
--- a/src/3d/Viewport3D.cpp
+++ b/src/3d/Viewport3D.cpp
@@ -7,6 +7,8 @@
 #include "EntityCollection3D.h"
 #include "Billboard.h"
 #include "Model3D.h"
+#include "VoxelGrid.h"
+#include "PyVoxelGrid.h"
 #include "../platform/GLContext.h"
 #include "PyVector.h"
 #include "PyColor.h"
@@ -62,6 +64,15 @@ Viewport3D::Viewport3D(float x, float y, float width, float height)
 Viewport3D::~Viewport3D() {
     cleanupTestGeometry();
     cleanupFBO();
+
+    // Clean up voxel VBO (Milestone 10)
+#ifdef MCRF_HAS_GL
+    if (voxelVBO_ != 0) {
+        glDeleteBuffers(1, &voxelVBO_);
+        voxelVBO_ = 0;
+    }
+#endif
+
     if (tcodMap_) {
         delete tcodMap_;
         tcodMap_ = nullptr;
@@ -836,6 +847,130 @@ void Viewport3D::renderMeshLayers() {
 #endif
 }
 
+// =============================================================================
+// Voxel Layer Management (Milestone 10)
+// =============================================================================
+
+void Viewport3D::addVoxelLayer(std::shared_ptr<VoxelGrid> grid, int zIndex) {
+    if (!grid) return;
+    voxelLayers_.push_back({grid, zIndex});
+
+    // Disable test cube when real content is added
+    renderTestCube_ = false;
+}
+
+bool Viewport3D::removeVoxelLayer(std::shared_ptr<VoxelGrid> grid) {
+    if (!grid) return false;
+
+    auto it = std::find_if(voxelLayers_.begin(), voxelLayers_.end(),
+                           [&grid](const auto& pair) { return pair.first == grid; });
+
+    if (it != voxelLayers_.end()) {
+        voxelLayers_.erase(it);
+        return true;
+    }
+    return false;
+}
+
+void Viewport3D::renderVoxelLayers(const mat4& view, const mat4& proj) {
+#ifdef MCRF_HAS_GL
+    if (voxelLayers_.empty() || !shader_ || !shader_->isValid()) {
+        return;
+    }
+
+    // Sort layers by z_index (lower = rendered first)
+    std::vector<std::pair<VoxelGrid*, int>> sortedLayers;
+    sortedLayers.reserve(voxelLayers_.size());
+    for (auto& pair : voxelLayers_) {
+        if (pair.first) {
+            sortedLayers.push_back({pair.first.get(), pair.second});
+        }
+    }
+    std::sort(sortedLayers.begin(), sortedLayers.end(),
+              [](const auto& a, const auto& b) { return a.second < b.second; });
+
+    shader_->bind();
+
+    // Set up view and projection matrices
+    shader_->setUniform("u_view", view);
+    shader_->setUniform("u_projection", proj);
+
+    // PS1 effect uniforms
+    shader_->setUniform("u_resolution", vec2(static_cast<float>(internalWidth_),
+                                               static_cast<float>(internalHeight_)));
+    shader_->setUniform("u_enable_snap", vertexSnapEnabled_);
+    shader_->setUniform("u_enable_dither", ditheringEnabled_);
+
+    // Lighting
+    vec3 lightDir = vec3(0.5f, -0.7f, 0.5f).normalized();
+    shader_->setUniform("u_light_dir", lightDir);
+    shader_->setUniform("u_ambient", vec3(0.3f, 0.3f, 0.3f));
+
+    // Fog
+    shader_->setUniform("u_fog_start", fogNear_);
+    shader_->setUniform("u_fog_end", fogFar_);
+    shader_->setUniform("u_fog_color", fogColor_);
+
+    // No texture for voxels (use vertex colors)
+    shader_->setUniform("u_has_texture", false);
+
+    // Create VBO if needed
+    if (voxelVBO_ == 0) {
+        glGenBuffers(1, &voxelVBO_);
+    }
+
+    // Render each voxel grid
+    for (auto& pair : sortedLayers) {
+        VoxelGrid* grid = pair.first;
+
+        // Get vertices (triggers rebuild if dirty)
+        const std::vector<MeshVertex>& vertices = grid->getVertices();
+        if (vertices.empty()) continue;
+
+        // Set model matrix for this grid
+        shader_->setUniform("u_model", grid->getModelMatrix());
+
+        // Upload vertices to VBO
+        glBindBuffer(GL_ARRAY_BUFFER, voxelVBO_);
+        glBufferData(GL_ARRAY_BUFFER,
+                     vertices.size() * sizeof(MeshVertex),
+                     vertices.data(),
+                     GL_DYNAMIC_DRAW);
+
+        // Set up vertex attributes (same as MeshLayer)
+        size_t stride = sizeof(MeshVertex);
+
+        // Position
+        glEnableVertexAttribArray(0);
+        glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, stride, (void*)offsetof(MeshVertex, position));
+
+        // TexCoord
+        glEnableVertexAttribArray(1);
+        glVertexAttribPointer(1, 2, GL_FLOAT, GL_FALSE, stride, (void*)offsetof(MeshVertex, texcoord));
+
+        // Normal
+        glEnableVertexAttribArray(2);
+        glVertexAttribPointer(2, 3, GL_FLOAT, GL_FALSE, stride, (void*)offsetof(MeshVertex, normal));
+
+        // Color
+        glEnableVertexAttribArray(3);
+        glVertexAttribPointer(3, 4, GL_FLOAT, GL_FALSE, stride, (void*)offsetof(MeshVertex, color));
+
+        // Draw
+        glDrawArrays(GL_TRIANGLES, 0, static_cast<GLsizei>(vertices.size()));
+
+        // Cleanup
+        glDisableVertexAttribArray(0);
+        glDisableVertexAttribArray(1);
+        glDisableVertexAttribArray(2);
+        glDisableVertexAttribArray(3);
+        glBindBuffer(GL_ARRAY_BUFFER, 0);
+    }
+
+    shader_->unbind();
+#endif
+}
+
 void Viewport3D::render3DContent() {
     // GL not available in current backend - skip 3D rendering
     if (!gl::isGLReady() || fbo_ == 0) {
@@ -879,9 +1014,12 @@ void Viewport3D::render3DContent() {
     // Render mesh layers first (terrain, etc.) - sorted by z_index
     renderMeshLayers();
 
-    // Render entities
+    // Render voxel layers (Milestone 10)
     mat4 view = camera_.getViewMatrix();
     mat4 projection = camera_.getProjectionMatrix();
+    renderVoxelLayers(view, projection);
+
+    // Render entities
     renderEntities(view, projection);
 
     // Render billboards (after opaque geometry for proper transparency)
@@ -2262,6 +2400,81 @@ static PyObject* Viewport3D_follow(PyViewport3DObject* self, PyObject* args, PyO
     Py_RETURN_NONE;
 }
 
+// =============================================================================
+// Voxel Layer Methods (Milestone 10)
+// =============================================================================
+
+static PyObject* Viewport3D_add_voxel_layer(PyViewport3DObject* self, PyObject* args, PyObject* kwds) {
+    static const char* kwlist[] = {"voxel_grid", "z_index", NULL};
+    PyObject* voxel_grid_obj = nullptr;
+    int z_index = 0;
+
+    if (!PyArg_ParseTupleAndKeywords(args, kwds, "O|i", const_cast<char**>(kwlist),
+                                      &voxel_grid_obj, &z_index)) {
+        return NULL;
+    }
+
+    // Check if it's a VoxelGrid object
+    PyTypeObject* voxelGridType = (PyTypeObject*)PyObject_GetAttrString(
+        McRFPy_API::mcrf_module, "VoxelGrid");
+    if (!voxelGridType) {
+        PyErr_SetString(PyExc_RuntimeError, "VoxelGrid type not found");
+        return NULL;
+    }
+
+    if (!PyObject_IsInstance(voxel_grid_obj, (PyObject*)voxelGridType)) {
+        Py_DECREF(voxelGridType);
+        PyErr_SetString(PyExc_TypeError, "voxel_grid must be a VoxelGrid object");
+        return NULL;
+    }
+    Py_DECREF(voxelGridType);
+
+    PyVoxelGridObject* vg = (PyVoxelGridObject*)voxel_grid_obj;
+    if (!vg->data) {
+        PyErr_SetString(PyExc_ValueError, "VoxelGrid not initialized");
+        return NULL;
+    }
+
+    self->data->addVoxelLayer(vg->data, z_index);
+    Py_RETURN_NONE;
+}
+
+static PyObject* Viewport3D_remove_voxel_layer(PyViewport3DObject* self, PyObject* args) {
+    PyObject* voxel_grid_obj = nullptr;
+
+    if (!PyArg_ParseTuple(args, "O", &voxel_grid_obj)) {
+        return NULL;
+    }
+
+    // Check if it's a VoxelGrid object
+    PyTypeObject* voxelGridType = (PyTypeObject*)PyObject_GetAttrString(
+        McRFPy_API::mcrf_module, "VoxelGrid");
+    if (!voxelGridType) {
+        PyErr_SetString(PyExc_RuntimeError, "VoxelGrid type not found");
+        return NULL;
+    }
+
+    if (!PyObject_IsInstance(voxel_grid_obj, (PyObject*)voxelGridType)) {
+        Py_DECREF(voxelGridType);
+        PyErr_SetString(PyExc_TypeError, "voxel_grid must be a VoxelGrid object");
+        return NULL;
+    }
+    Py_DECREF(voxelGridType);
+
+    PyVoxelGridObject* vg = (PyVoxelGridObject*)voxel_grid_obj;
+    if (!vg->data) {
+        PyErr_SetString(PyExc_ValueError, "VoxelGrid not initialized");
+        return NULL;
+    }
+
+    bool removed = self->data->removeVoxelLayer(vg->data);
+    return PyBool_FromLong(removed);
+}
+
+static PyObject* Viewport3D_voxel_layer_count(PyViewport3DObject* self, PyObject* Py_UNUSED(args)) {
+    return PyLong_FromSize_t(self->data->getVoxelLayerCount());
+}
+
 } // namespace mcrf
 
 // Methods array - outside namespace but PyObjectType still in scope via typedef
@@ -2441,5 +2654,25 @@ PyMethodDef Viewport3D_methods[] = {
      "    distance: Distance behind entity\n"
      "    height: Camera height above entity\n"
      "    smoothing: Interpolation factor (0-1). 1 = instant, lower = smoother"},
+
+    // Voxel layer methods (Milestone 10)
+    {"add_voxel_layer", (PyCFunction)mcrf::Viewport3D_add_voxel_layer, METH_VARARGS | METH_KEYWORDS,
+     "add_voxel_layer(voxel_grid, z_index=0)\n\n"
+     "Add a VoxelGrid as a renderable layer.\n\n"
+     "Args:\n"
+     "    voxel_grid: VoxelGrid object to render\n"
+     "    z_index: Render order (lower = rendered first)"},
+    {"remove_voxel_layer", (PyCFunction)mcrf::Viewport3D_remove_voxel_layer, METH_VARARGS,
+     "remove_voxel_layer(voxel_grid) -> bool\n\n"
+     "Remove a VoxelGrid layer from the viewport.\n\n"
+     "Args:\n"
+     "    voxel_grid: VoxelGrid object to remove\n\n"
+     "Returns:\n"
+     "    True if the layer was found and removed"},
+    {"voxel_layer_count", (PyCFunction)mcrf::Viewport3D_voxel_layer_count, METH_NOARGS,
+     "voxel_layer_count() -> int\n\n"
+     "Get the number of voxel layers.\n\n"
+     "Returns:\n"
+     "    Number of voxel layers in the viewport"},
     {NULL}  // Sentinel
 };
diff --git a/src/3d/Viewport3D.h b/src/3d/Viewport3D.h
index 780c1ee..59b8b59 100644
--- a/src/3d/Viewport3D.h
+++ b/src/3d/Viewport3D.h
@@ -31,6 +31,7 @@ class Viewport3D;
 class Shader3D;
 class MeshLayer;
 class Billboard;
+class VoxelGrid;
 
 } // namespace mcrf
 
@@ -226,6 +227,29 @@ public:
     /// Render all billboards
     void renderBillboards(const mat4& view, const mat4& proj);
 
+    // =========================================================================
+    // VoxelGrid Layer Management (Milestone 10)
+    // =========================================================================
+
+    /// Add a voxel layer to the viewport
+    /// @param grid The VoxelGrid to add
+    /// @param zIndex Render order (lower = rendered first, behind higher values)
+    void addVoxelLayer(std::shared_ptr<VoxelGrid> grid, int zIndex = 0);
+
+    /// Remove a voxel layer from the viewport
+    /// @param grid The VoxelGrid to remove
+    /// @return true if the layer was found and removed
+    bool removeVoxelLayer(std::shared_ptr<VoxelGrid> grid);
+
+    /// Get all voxel layers (read-only)
+    const std::vector<std::pair<std::shared_ptr<VoxelGrid>, int>>& getVoxelLayers() const { return voxelLayers_; }
+
+    /// Get number of voxel layers
+    size_t getVoxelLayerCount() const { return voxelLayers_.size(); }
+
+    /// Render all voxel layers
+    void renderVoxelLayers(const mat4& view, const mat4& proj);
+
     // Background color
     void setBackgroundColor(const sf::Color& color) { bgColor_ = color; }
     sf::Color getBackgroundColor() const { return bgColor_; }
@@ -319,6 +343,11 @@ private:
     // Billboard storage
     std::shared_ptr<std::vector<std::shared_ptr<Billboard>>> billboards_;
 
+    // Voxel layer storage (Milestone 10)
+    // Pairs of (VoxelGrid, z_index) for render ordering
+    std::vector<std::pair<std::shared_ptr<VoxelGrid>, int>> voxelLayers_;
+    unsigned int voxelVBO_ = 0;  // Shared VBO for voxel rendering
+
     // Shader for PS1-style rendering
     std::unique_ptr<Shader3D> shader_;
     std::unique_ptr<Shader3D> skinnedShader_;  // For skeletal animation
diff --git a/src/3d/VoxelGrid.cpp b/src/3d/VoxelGrid.cpp
new file mode 100644
index 0000000..2c3ed34
--- /dev/null
+++ b/src/3d/VoxelGrid.cpp
@@ -0,0 +1,171 @@
+// VoxelGrid.cpp - Dense 3D voxel array implementation
+// Part of McRogueFace 3D Extension - Milestones 9-10
+
+#include "VoxelGrid.h"
+#include "VoxelMesher.h"
+#include "MeshLayer.h"  // For MeshVertex
+
+namespace mcrf {
+
+// Static air material for out-of-bounds or ID=0 queries
+static VoxelMaterial airMaterial{"air", sf::Color::Transparent, -1, true, 0.0f};
+
+// =============================================================================
+// Constructor
+// =============================================================================
+
+VoxelGrid::VoxelGrid(int w, int h, int d, float cellSize)
+    : width_(w), height_(h), depth_(d), cellSize_(cellSize),
+      offset_(0, 0, 0), rotation_(0.0f)
+{
+    if (w <= 0 || h <= 0 || d <= 0) {
+        throw std::invalid_argument("VoxelGrid dimensions must be positive");
+    }
+    if (cellSize <= 0.0f) {
+        throw std::invalid_argument("VoxelGrid cell size must be positive");
+    }
+
+    // Allocate dense array, initialized to air (0)
+    size_t totalSize = static_cast<size_t>(w) * h * d;
+    data_.resize(totalSize, 0);
+}
+
+// =============================================================================
+// Per-voxel access
+// =============================================================================
+
+bool VoxelGrid::isValid(int x, int y, int z) const {
+    return x >= 0 && x < width_ &&
+           y >= 0 && y < height_ &&
+           z >= 0 && z < depth_;
+}
+
+uint8_t VoxelGrid::get(int x, int y, int z) const {
+    if (!isValid(x, y, z)) {
+        return 0;  // Out of bounds returns air
+    }
+    return data_[index(x, y, z)];
+}
+
+void VoxelGrid::set(int x, int y, int z, uint8_t material) {
+    if (!isValid(x, y, z)) {
+        return;  // Out of bounds is no-op
+    }
+    data_[index(x, y, z)] = material;
+    meshDirty_ = true;
+}
+
+// =============================================================================
+// Material palette
+// =============================================================================
+
+uint8_t VoxelGrid::addMaterial(const VoxelMaterial& mat) {
+    if (materials_.size() >= 255) {
+        throw std::runtime_error("Material palette full (max 255 materials)");
+    }
+    materials_.push_back(mat);
+    return static_cast<uint8_t>(materials_.size());  // 1-indexed
+}
+
+uint8_t VoxelGrid::addMaterial(const std::string& name, sf::Color color,
+                               int spriteIndex, bool transparent, float pathCost) {
+    return addMaterial(VoxelMaterial(name, color, spriteIndex, transparent, pathCost));
+}
+
+const VoxelMaterial& VoxelGrid::getMaterial(uint8_t id) const {
+    if (id == 0 || id > materials_.size()) {
+        return airMaterial;
+    }
+    return materials_[id - 1];  // 1-indexed, so ID 1 = materials_[0]
+}
+
+// =============================================================================
+// Bulk operations
+// =============================================================================
+
+void VoxelGrid::fill(uint8_t material) {
+    std::fill(data_.begin(), data_.end(), material);
+    meshDirty_ = true;
+}
+
+// =============================================================================
+// Transform
+// =============================================================================
+
+mat4 VoxelGrid::getModelMatrix() const {
+    // Apply translation first, then rotation around Y axis
+    mat4 translation = mat4::translate(offset_);
+    mat4 rotation = mat4::rotateY(rotation_ * DEG_TO_RAD);
+    return translation * rotation;
+}
+
+// =============================================================================
+// Statistics
+// =============================================================================
+
+size_t VoxelGrid::countNonAir() const {
+    size_t count = 0;
+    for (uint8_t v : data_) {
+        if (v != 0) {
+            count++;
+        }
+    }
+    return count;
+}
+
+size_t VoxelGrid::countMaterial(uint8_t material) const {
+    size_t count = 0;
+    for (uint8_t v : data_) {
+        if (v == material) {
+            count++;
+        }
+    }
+    return count;
+}
+
+// =============================================================================
+// fillBox (Milestone 10)
+// =============================================================================
+
+void VoxelGrid::fillBox(int x0, int y0, int z0, int x1, int y1, int z1, uint8_t material) {
+    // Ensure proper ordering (min to max)
+    if (x0 > x1) std::swap(x0, x1);
+    if (y0 > y1) std::swap(y0, y1);
+    if (z0 > z1) std::swap(z0, z1);
+
+    // Clamp to valid range
+    x0 = std::max(0, std::min(x0, width_ - 1));
+    x1 = std::max(0, std::min(x1, width_ - 1));
+    y0 = std::max(0, std::min(y0, height_ - 1));
+    y1 = std::max(0, std::min(y1, height_ - 1));
+    z0 = std::max(0, std::min(z0, depth_ - 1));
+    z1 = std::max(0, std::min(z1, depth_ - 1));
+
+    for (int z = z0; z <= z1; z++) {
+        for (int y = y0; y <= y1; y++) {
+            for (int x = x0; x <= x1; x++) {
+                data_[index(x, y, z)] = material;
+            }
+        }
+    }
+    meshDirty_ = true;
+}
+
+// =============================================================================
+// Mesh Caching (Milestone 10)
+// =============================================================================
+
+const std::vector<MeshVertex>& VoxelGrid::getVertices() const {
+    if (meshDirty_) {
+        rebuildMesh();
+    }
+    return cachedVertices_;
+}
+
+void VoxelGrid::rebuildMesh() const {
+    cachedVertices_.clear();
+    VoxelMesher::generateMesh(*this, cachedVertices_);
+    meshDirty_ = false;
+}
+
+} // namespace mcrf
diff --git a/src/3d/VoxelGrid.h b/src/3d/VoxelGrid.h
new file mode 100644
index 0000000..3f6447a
--- /dev/null
+++ b/src/3d/VoxelGrid.h
@@ -0,0 +1,121 @@
+// VoxelGrid.h - Dense 3D voxel array with material palette
+// Part of McRogueFace 3D Extension - Milestones 9-10
+#pragma once
+
+#include "../Common.h"
+#include "Math3D.h"
+#include "MeshLayer.h"  // For MeshVertex (needed for std::vector<MeshVertex>)
+#include <vector>
+#include <string>
+#include <stdexcept>
+
+namespace mcrf {
+
+// =============================================================================
+// VoxelMaterial - Properties for a voxel material type
+// =============================================================================
+
+struct VoxelMaterial {
+    std::string name;
+    sf::Color color;           // Fallback solid color
+    int spriteIndex = -1;      // Texture atlas index (-1 = use color)
+    bool transparent = false;  // For FOV projection and face culling
+    float pathCost = 1.0f;     // Navigation cost multiplier (0 = impassable)
+
+    VoxelMaterial() : name("unnamed"), color(sf::Color::White) {}
+    VoxelMaterial(const std::string& n, sf::Color c, int sprite = -1,
+                  bool transp = false, float cost = 1.0f)
+        : name(n), color(c), spriteIndex(sprite), transparent(transp), pathCost(cost) {}
+};
+
+// =============================================================================
+// VoxelGrid - Dense 3D array of material IDs
+// =============================================================================
+
+class VoxelGrid {
+private:
+    int width_, height_, depth_;
+    float cellSize_;
+    std::vector<uint8_t> data_;          // Material ID per cell (0 = air)
+    std::vector<VoxelMaterial> materials_;
+
+    // Transform
+    vec3 offset_;
+    float rotation_ = 0.0f;  // Y-axis only, degrees
+
+    // Mesh caching (Milestone 10)
+    mutable bool meshDirty_ = true;
+    mutable std::vector<MeshVertex> cachedVertices_;
+
+    // Index calculation (row-major: X varies fastest, then Y, then Z)
+    inline size_t index(int x, int y, int z) const {
+        return static_cast<size_t>(z) * (width_ * height_) +
+               static_cast<size_t>(y) * width_ +
+               static_cast<size_t>(x);
+    }
+
+public:
+    // Constructor
+    VoxelGrid(int w, int h, int d, float cellSize = 1.0f);
+
+    // Dimensions (read-only)
+    int width() const { return width_; }
+    int height() const { return height_; }
+    int depth() const { return depth_; }
+    float cellSize() const { return cellSize_; }
+    size_t totalVoxels() const { return static_cast<size_t>(width_) * height_ * depth_; }
+
+    // Per-voxel access
+    uint8_t get(int x, int y, int z) const;
+    void set(int x, int y, int z, uint8_t material);
+    bool isValid(int x, int y, int z) const;
+
+    // Material palette
+    // Returns 1-indexed material ID (0 = air, always implicit)
+    uint8_t addMaterial(const VoxelMaterial& mat);
+    uint8_t addMaterial(const std::string& name, sf::Color color,
+                        int spriteIndex = -1, bool transparent = false,
+                        float pathCost = 1.0f);
+    const VoxelMaterial& getMaterial(uint8_t id) const;
+    size_t materialCount() const { return materials_.size(); }
+
+    // Bulk operations
+    void fill(uint8_t material);
+    void clear() { fill(0); }
+    void fillBox(int x0, int y0, int z0, int x1, int y1, int z1, uint8_t material);
+
+    // Transform
+    void setOffset(const vec3& offset) { offset_ = offset; }
+    void setOffset(float x, float y, float z) { offset_ = vec3(x, y, z); }
+    vec3 getOffset() const { return offset_; }
+    void setRotation(float degrees) { rotation_ = degrees; }
+    float getRotation() const { return rotation_; }
+    mat4 getModelMatrix() const;
+
+    // Statistics
+    size_t countNonAir() const;
+    size_t countMaterial(uint8_t material) const;
+
+    // Mesh caching (Milestone 10)
+    /// Mark mesh as needing rebuild (called automatically by set/fill operations)
+    void markDirty() { meshDirty_ = true; }
+
+    /// Check if mesh needs rebuild
+    bool isMeshDirty() const { return meshDirty_; }
+
+    /// Get vertices for rendering (rebuilds mesh if dirty)
+    const std::vector<MeshVertex>& getVertices() const;
+
+    /// Force immediate mesh rebuild
+    void rebuildMesh() const;
+
+    /// Get vertex count after mesh generation
+    size_t vertexCount() const { return cachedVertices_.size(); }
+
+    // Memory info (for debugging)
+    size_t memoryUsageBytes() const {
+        return data_.size() + materials_.size() * sizeof(VoxelMaterial);
+    }
+};
+
+} // namespace mcrf
diff --git a/src/3d/VoxelMesher.cpp b/src/3d/VoxelMesher.cpp
new file mode 100644
index 0000000..ee7df0d
--- /dev/null
+++ b/src/3d/VoxelMesher.cpp
@@ -0,0 +1,136 @@
+// VoxelMesher.cpp - Face-culled mesh generation for VoxelGrid
+// Part of McRogueFace 3D Extension - Milestone 10
+
+#include "VoxelMesher.h"
+#include <cmath>
+
+namespace mcrf {
+
+void VoxelMesher::generateMesh(const VoxelGrid& grid, std::vector<MeshVertex>& outVertices) {
+    const float cs = grid.cellSize();
+
+    for (int z = 0; z < grid.depth(); z++) {
+        for (int y = 0; y < grid.height(); y++) {
+            for (int x = 0; x < grid.width(); x++) {
+                uint8_t mat = grid.get(x, y, z);
+                if (mat == 0) continue;  // Skip air
+
+                const VoxelMaterial& material = grid.getMaterial(mat);
+
+                // Voxel center in local space
+                vec3 center((x + 0.5f) * cs, (y + 0.5f) * cs, (z + 0.5f) * cs);
+
+                // Check each face direction
+                // +X face
+                if (shouldGenerateFace(grid, x, y, z, x + 1, y, z)) {
+                    emitFace(outVertices, center, vec3(1, 0, 0), cs, material);
+                }
+                // -X face
+                if (shouldGenerateFace(grid, x, y, z, x - 1, y, z)) {
+                    emitFace(outVertices, center, vec3(-1, 0, 0), cs, material);
+                }
+                // +Y face (top)
+                if (shouldGenerateFace(grid, x, y, z, x, y + 1, z)) {
+                    emitFace(outVertices, center, vec3(0, 1, 0), cs, material);
+                }
+                // -Y face (bottom)
+                if (shouldGenerateFace(grid, x, y, z, x, y - 1, z)) {
+                    emitFace(outVertices, center, vec3(0, -1, 0), cs, material);
+                }
+                // +Z face
+                if (shouldGenerateFace(grid, x, y, z, x, y, z + 1)) {
+                    emitFace(outVertices, center, vec3(0, 0, 1), cs, material);
+                }
+                // -Z face
+                if (shouldGenerateFace(grid, x, y, z, x, y, z - 1)) {
+                    emitFace(outVertices, center, vec3(0, 0, -1), cs, material);
+                }
+            }
+        }
+    }
+}
+
+bool VoxelMesher::shouldGenerateFace(const VoxelGrid& grid,
+                                      int x, int y, int z,
+                                      int nx, int ny, int nz) {
+    // Out of bounds = air, so generate face
+    if (!grid.isValid(nx, ny, nz)) {
+        return true;
+    }
+
+    uint8_t neighbor = grid.get(nx, ny, nz);
+
+    // Air neighbor = generate face
+    if (neighbor == 0) {
+        return true;
+    }
+
+    // Check if neighbor is transparent
+    // Transparent materials allow faces to be visible behind them
+    return grid.getMaterial(neighbor).transparent;
+}
+
+void VoxelMesher::emitFace(std::vector<MeshVertex>& vertices,
+                            const vec3& center,
+                            const vec3& normal,
+                            float size,
+                            const VoxelMaterial& material) {
+    // Calculate face corners based on normal direction
+    vec3 up, right;
+
+    if (std::abs(normal.y) > 0.5f) {
+        // Horizontal face (floor/ceiling)
+        // For +Y (top), we want the face to look correct from above
+        // For -Y (bottom), we want it to look correct from below
+        up = vec3(0, 0, normal.y);    // Z direction based on face direction
+        right = vec3(1, 0, 0);         // Always X axis for horizontal faces
+    } else if (std::abs(normal.x) > 0.5f) {
+        // X-facing wall
+        up = vec3(0, 1, 0);            // Y axis is up
+        right = vec3(0, 0, normal.x);  // Z direction based on face direction
+    } else {
+        // Z-facing wall
+        up = vec3(0, 1, 0);            // Y axis is up
+        right = vec3(-normal.z, 0, 0); // X direction based on face direction
+    }
+
+    float halfSize = size * 0.5f;
+    vec3 faceCenter = center + normal * halfSize;
+
+    // 4 corners of the face
+    vec3 corners[4] = {
+        faceCenter - right * halfSize - up * halfSize,  // Bottom-left
+        faceCenter + right * halfSize - up * halfSize,  // Bottom-right
+        faceCenter + right * halfSize + up * halfSize,  // Top-right
+        faceCenter - right * halfSize + up * halfSize   // Top-left
+    };
+
+    // UV coordinates (solid color or single sprite tile)
+    vec2 uvs[4] = {
+        vec2(0, 0),  // Bottom-left
+        vec2(1, 0),  // Bottom-right
+        vec2(1, 1),  // Top-right
+        vec2(0, 1)   // Top-left
+    };
+
+    // Color from material (convert 0-255 to 0-1)
+    vec4 color(
+        material.color.r / 255.0f,
+        material.color.g / 255.0f,
+        material.color.b / 255.0f,
+        material.color.a / 255.0f
+    );
+
+    // Emit 2 triangles (6 vertices) - CCW winding for OpenGL front faces
+    // Triangle 1: 0-2-1 (bottom-left, top-right, bottom-right) - CCW
+    vertices.push_back(MeshVertex(corners[0], uvs[0], normal, color));
+    vertices.push_back(MeshVertex(corners[2], uvs[2], normal, color));
+    vertices.push_back(MeshVertex(corners[1], uvs[1], normal, color));
+
+    // Triangle 2: 0-3-2 (bottom-left, top-left, top-right) - CCW
+    vertices.push_back(MeshVertex(corners[0], uvs[0], normal, color));
+    vertices.push_back(MeshVertex(corners[3], uvs[3], normal, color));
+    vertices.push_back(MeshVertex(corners[2], uvs[2], normal, color));
+}
+
+} // namespace mcrf
diff --git a/src/3d/VoxelMesher.h b/src/3d/VoxelMesher.h
new file mode 100644
index 0000000..9dc87c4
--- /dev/null
+++ b/src/3d/VoxelMesher.h
@@ -0,0 +1,53 @@
+// VoxelMesher.h - Face-culled mesh generation for VoxelGrid
+// Part of McRogueFace 3D Extension - Milestone 10
+#pragma once
+
+#include "VoxelGrid.h"
+#include "MeshLayer.h"  // For MeshVertex
+#include <vector>
+
+namespace mcrf {
+
+// =============================================================================
+// VoxelMesher - Static class for generating triangle meshes from VoxelGrid
+// =============================================================================
+
+class VoxelMesher {
+public:
+    /// Generate face-culled mesh from voxel data
+    /// Output vertices in local space (model matrix applies world transform)
+    /// @param grid The VoxelGrid to generate mesh from
+    /// @param outVertices Output vector of vertices (appended to, not cleared)
+    static void generateMesh(
+        const VoxelGrid& grid,
+        std::vector<MeshVertex>& outVertices
+    );
+
+private:
+    /// Check if face should be generated (neighbor is air or transparent)
+    /// @param grid The VoxelGrid
+    /// @param x, y, z Current voxel position
+    /// @param nx, ny, nz Neighbor voxel position
+    /// @return true if face should be generated
+    static bool shouldGenerateFace(
+        const VoxelGrid& grid,
+        int x, int y, int z,
+        int nx, int ny, int nz
+    );
+
+    /// Generate a single face (2 triangles = 6 vertices)
+    /// @param vertices Output vector to append vertices to
+    /// @param center Center of the voxel
+    /// @param normal Face normal direction
+    /// @param size Voxel cell size
+    /// @param material Material for coloring
+    static void emitFace(
+        std::vector<MeshVertex>& vertices,
+        const vec3& center,
+        const vec3& normal,
+        float size,
+        const VoxelMaterial& material
+    );
+};
+
+} // namespace mcrf
diff --git a/src/McRFPy_API.cpp b/src/McRFPy_API.cpp
index c6b0ad2..6a67dec 100644
--- a/src/McRFPy_API.cpp
+++ b/src/McRFPy_API.cpp
@@ -36,6 +36,7 @@
 #include "3d/EntityCollection3D.h"  // Entity3D collection
 #include "3d/Model3D.h"     // 3D model resource
 #include "3d/Billboard.h"   // Billboard sprites
+#include "3d/PyVoxelGrid.h" // Voxel grid for 3D structures (Milestone 9)
 #include "McRogueFaceVersion.h"
 #include "GameEngine.h"
 // ImGui is only available for SFML builds
@@ -442,7 +443,7 @@ PyObject* PyInit_mcrfpy()
         /*3D entities*/
         &mcrfpydef::PyEntity3DType, &mcrfpydef::PyEntityCollection3DType,
         &mcrfpydef::PyEntityCollection3DIterType, &mcrfpydef::PyModel3DType,
-        &mcrfpydef::PyBillboardType,
+        &mcrfpydef::PyBillboardType, &mcrfpydef::PyVoxelGridType,
 
         /*grid layers (#147)*/
         &PyColorLayerType, &PyTileLayerType,
@@ -539,6 +540,10 @@ PyObject* PyInit_mcrfpy()
     mcrfpydef::PyNoiseSourceType.tp_methods = PyNoiseSource::methods;
     mcrfpydef::PyNoiseSourceType.tp_getset = PyNoiseSource::getsetters;
 
+    // Set up PyVoxelGridType methods and getsetters (Milestone 9)
+    mcrfpydef::PyVoxelGridType.tp_methods = PyVoxelGrid::methods;
+    mcrfpydef::PyVoxelGridType.tp_getset = PyVoxelGrid::getsetters;
+
     // Set up PyShaderType methods and getsetters (#106)
     mcrfpydef::PyShaderType.tp_methods = PyShader::methods;
     mcrfpydef::PyShaderType.tp_getset = PyShader::getsetters;
diff --git a/tests/demo/screens/voxel_meshing_demo.py b/tests/demo/screens/voxel_meshing_demo.py
new file mode 100644
index 0000000..862002b
--- /dev/null
+++ b/tests/demo/screens/voxel_meshing_demo.py
@@ -0,0 +1,218 @@
+# voxel_meshing_demo.py - Visual demo of VoxelGrid mesh rendering
+# Shows voxel building rendered in Viewport3D with PS1 effects
+
+import mcrfpy
+import sys
+import math
+
+# Create demo scene
+scene = mcrfpy.Scene("voxel_meshing_demo")
+
+# Dark background frame
+bg = mcrfpy.Frame(pos=(0, 0), size=(1024, 768), fill_color=mcrfpy.Color(15, 15, 25))
+scene.children.append(bg)
+
+# Title
+title = mcrfpy.Caption(text="VoxelGrid Meshing Demo - Face-Culled 3D Voxels", pos=(20, 10))
+title.fill_color = mcrfpy.Color(255, 255, 255)
+scene.children.append(title)
+
+# Create the 3D viewport
+viewport = mcrfpy.Viewport3D(
+    pos=(50, 60),
+    size=(600, 500),
+    render_resolution=(320, 240),  # PS1 resolution
+    fov=60.0,
+    camera_pos=(20.0, 15.0, 20.0),
+    camera_target=(4.0, 2.0, 4.0),
+    bg_color=mcrfpy.Color(50, 70, 100)  # Sky color
+)
+scene.children.append(viewport)
+
+# Create voxel grid for building
+print("Creating voxel building...")
+voxels = mcrfpy.VoxelGrid(size=(12, 8, 12), cell_size=1.0)
+
+# Define materials
+STONE = voxels.add_material("stone", color=mcrfpy.Color(128, 128, 128))
+BRICK = voxels.add_material("brick", color=mcrfpy.Color(165, 82, 42))
+WOOD = voxels.add_material("wood", color=mcrfpy.Color(139, 90, 43))
+GLASS = voxels.add_material("glass", color=mcrfpy.Color(180, 220, 255, 180), transparent=True)
+GRASS = voxels.add_material("grass", color=mcrfpy.Color(60, 150, 60))
+
+print(f"Defined {voxels.material_count} materials")
+
+# Build a simple house structure
+
+# Ground/foundation
+voxels.fill_box((0, 0, 0), (11, 0, 11), GRASS)
+
+# Floor
+voxels.fill_box((1, 1, 1), (10, 1, 10), STONE)
+
+# Walls
+# Front wall (Z=1)
+voxels.fill_box((1, 2, 1), (10, 5, 1), BRICK)
+# Back wall (Z=10)
+voxels.fill_box((1, 2, 10), (10, 5, 10), BRICK)
+# Left wall (X=1)
+voxels.fill_box((1, 2, 1), (1, 5, 10), BRICK)
+# Right wall (X=10)
+voxels.fill_box((10, 2, 1), (10, 5, 10), BRICK)
+
+# Door opening (front wall)
+voxels.fill_box((4, 2, 1), (6, 4, 1), 0)  # Clear door opening
+
+# Windows
+# Front windows (beside door)
+voxels.fill_box((2, 3, 1), (3, 4, 1), GLASS)
+voxels.fill_box((8, 3, 1), (9, 4, 1), GLASS)
+# Side windows
+voxels.fill_box((1, 3, 4), (1, 4, 5), GLASS)
+voxels.fill_box((1, 3, 7), (1, 4, 8), GLASS)
+voxels.fill_box((10, 3, 4), (10, 4, 5), GLASS)
+voxels.fill_box((10, 3, 7), (10, 4, 8), GLASS)
+
+# Ceiling
+voxels.fill_box((1, 6, 1), (10, 6, 10), WOOD)
+
+# Simple roof (peaked)
+voxels.fill_box((0, 7, 0), (11, 7, 11), WOOD)
+voxels.fill_box((1, 8, 1), (10, 8, 10), WOOD)
+voxels.fill_box((2, 9, 2), (9, 9, 9), WOOD)
+voxels.fill_box((3, 10, 3), (8, 10, 8), WOOD)
+voxels.fill_box((4, 11, 4), (7, 11, 7), WOOD)
+
+# Build the mesh
+voxels.rebuild_mesh()
+
+print(f"Built voxel house:")
+print(f"  Non-air voxels: {voxels.count_non_air()}")
+print(f"  Vertices: {voxels.vertex_count}")
+print(f"  Faces: {voxels.vertex_count // 6}")
+
+# Position the building
+voxels.offset = (0.0, 0.0, 0.0)
+voxels.rotation = 0.0
+
+# Add to viewport
+viewport.add_voxel_layer(voxels, z_index=0)
+print(f"Added voxel layer to viewport (count: {viewport.voxel_layer_count()})")
+
+# Create info panel
+info_frame = mcrfpy.Frame(pos=(680, 60), size=(300, 250), fill_color=mcrfpy.Color(40, 40, 60, 200))
+scene.children.append(info_frame)
+
+info_title = mcrfpy.Caption(text="Building Stats", pos=(690, 70))
+info_title.fill_color = mcrfpy.Color(255, 255, 100)
+scene.children.append(info_title)
+
+stats_text = f"""Grid: {voxels.width}x{voxels.height}x{voxels.depth}
+Total voxels: {voxels.width * voxels.height * voxels.depth}
+Non-air: {voxels.count_non_air()}
+Materials: {voxels.material_count}
+Vertices: {voxels.vertex_count}
+Faces: {voxels.vertex_count // 6}
+
+Without culling would be:
+  {voxels.count_non_air() * 36} vertices
+  ({100 - (voxels.vertex_count / (voxels.count_non_air() * 36) * 100):.0f}% reduction)"""
+
+stats = mcrfpy.Caption(text=stats_text, pos=(690, 100))
+stats.fill_color = mcrfpy.Color(200, 200, 200)
+scene.children.append(stats)
+
+# Controls info
+controls_frame = mcrfpy.Frame(pos=(680, 330), size=(300, 180), fill_color=mcrfpy.Color(40, 40, 60, 200))
+scene.children.append(controls_frame)
+
+controls_title = mcrfpy.Caption(text="Controls", pos=(690, 340))
+controls_title.fill_color = mcrfpy.Color(255, 255, 100)
+scene.children.append(controls_title)
+
+controls_text = """R - Toggle rotation
+1-5 - Change camera angle
+SPACE - Reset camera
+ESC - Exit demo"""
+
+controls = mcrfpy.Caption(text=controls_text, pos=(690, 370))
+controls.fill_color = mcrfpy.Color(200, 200, 200)
+scene.children.append(controls)
+
+# Animation state
+rotation_enabled = False
+current_angle = 0.0
+camera_angles = [
+    (20.0, 15.0, 20.0),   # Default - diagonal view
+    (0.0, 15.0, 25.0),    # Front view
+    (25.0, 15.0, 0.0),    # Side view
+    (5.5, 25.0, 5.5),     # Top-down view
+    (5.5, 3.0, 20.0),     # Low angle
+]
+current_camera = 0
+
+def rotate_building(timer, runtime):
+    """Timer callback for building rotation"""
+    global current_angle, rotation_enabled
+    if rotation_enabled:
+        current_angle += 1.0
+        if current_angle >= 360.0:
+            current_angle = 0.0
+        voxels.rotation = current_angle
+
+# Set up rotation timer
+timer = mcrfpy.Timer("rotate", rotate_building, 33)  # ~30 FPS
+
+def handle_key(key, action):
+    """Keyboard handler"""
+    global rotation_enabled, current_camera
+    if action != mcrfpy.InputState.PRESSED:
+        return
+
+    if key == mcrfpy.Key.R:
+        rotation_enabled = not rotation_enabled
+        print(f"Rotation: {'ON' if rotation_enabled else 'OFF'}")
+    elif key == mcrfpy.Key.NUM_1:
+        current_camera = 0
+        viewport.camera_pos = camera_angles[0]
+        print("Camera: Default diagonal")
+    elif key == mcrfpy.Key.NUM_2:
+        current_camera = 1
+        viewport.camera_pos = camera_angles[1]
+        print("Camera: Front view")
+    elif key == mcrfpy.Key.NUM_3:
+        current_camera = 2
+        viewport.camera_pos = camera_angles[2]
+        print("Camera: Side view")
+    elif key == mcrfpy.Key.NUM_4:
+        current_camera = 3
+        viewport.camera_pos = camera_angles[3]
+        print("Camera: Top-down view")
+    elif key == mcrfpy.Key.NUM_5:
+        current_camera = 4
+        viewport.camera_pos = camera_angles[4]
+        print("Camera: Low angle")
+    elif key == mcrfpy.Key.SPACE:
+        current_camera = 0
+        voxels.rotation = 0.0
+        viewport.camera_pos = camera_angles[0]
+        print("Camera: Reset")
+    elif key == mcrfpy.Key.ESCAPE:
+        print("Exiting demo...")
+        sys.exit(0)
+
+scene.on_key = handle_key
+
+# Activate the scene
+mcrfpy.current_scene = scene
+print("Voxel Meshing Demo ready! Press R to toggle rotation.")
+
+# Main entry point for --exec mode
+if __name__ == "__main__":
+    # Demo is set up, print summary
+    print("\n=== Voxel Meshing Demo Summary ===")
+    print(f"Grid size: {voxels.width}x{voxels.height}x{voxels.depth}")
+    print(f"Non-air voxels: {voxels.count_non_air()}")
+    print(f"Generated vertices: {voxels.vertex_count}")
+    print(f"Rendered faces: {voxels.vertex_count // 6}")
+    print("===================================\n")