matplotlib · Vikash-Kumar-23 · Jun 12, 2026 · Jun 13, 2026 · Jun 13, 2026 · Jun 13, 2026
diff --git a/lib/matplotlib/backend_bases.py b/lib/matplotlib/backend_bases.py
@@ -1730,6 +1730,7 @@ class FigureCanvasBase:
     events = [
         'resize_event',
         'draw_event',
+        'pre_draw_event',
         'key_press_event',
         'key_release_event',
         'button_press_event',
@@ -2333,6 +2334,7 @@ def mpl_connect(self, s, func):
             - 'button_press_event'
             - 'button_release_event'
             - 'draw_event'
+            - 'pre_draw_event'
             - 'key_press_event'
             - 'key_release_event'
             - 'motion_notify_event'

diff --git a/lib/matplotlib/figure.py b/lib/matplotlib/figure.py
@@ -3268,7 +3268,6 @@ def draw(self, renderer):
 
         with self._render_lock:
 
-            artists = self._get_draw_artists(renderer)
             try:
                 renderer.open_group('figure', gid=self.get_gid())
                 if self.axes and self.get_layout_engine() is not None:
@@ -3278,6 +3277,9 @@ def draw(self, renderer):
                         pass
                         # ValueError can occur when resizing a window.
 
+                artists = self._get_draw_artists(renderer)
+                DrawEvent("pre_draw_event", self.canvas, renderer)._process()
+
                 self.patch.draw(renderer)
                 mimage._draw_list_compositing_images(
                     renderer, self, artists, self.suppressComposite)

diff --git a/lib/matplotlib/tests/test_figure.py b/lib/matplotlib/tests/test_figure.py
@@ -1900,3 +1900,64 @@ def test_figsize_both_none():
 def test_figsize_invalid_unit():
     with pytest.raises(ValueError, match="Invalid unit 'um'"):
         plt.figure(figsize=(6, 4, "um"))
+
+
+def test_pre_draw_event_emitted():
+    fig, ax = plt.subplots()
+    count = []
+    fig.canvas.mpl_connect('pre_draw_event', lambda e: count.append(1))
+    fig.canvas.draw()
+    assert len(count) == 1
+
+
+def test_pre_draw_event_before_draw_event():
+    fig, ax = plt.subplots()
+    order = []
+    fig.canvas.mpl_connect('pre_draw_event', lambda e: order.append('pre'))
+    fig.canvas.mpl_connect('draw_event', lambda e: order.append('draw'))
+    fig.canvas.draw()
+    assert order == ['pre', 'draw']
+
+
+def test_pre_draw_event_axes_geometry_finalized():
+    fig, axs = plt.subplots(2, 2, constrained_layout=True)
+    for ax in axs.flat:
+        ax.plot([1, 2, 3], [1, 4, 2])
+
+    pre_positions = []
+    draw_positions = []
+
+    def on_pre(event):
+        pre_positions.extend(ax.get_position().bounds for ax in axs.flat)
+
+    def on_draw(event):
+        draw_positions.extend(ax.get_position().bounds for ax in axs.flat)
+
+    fig.canvas.mpl_connect('pre_draw_event', on_pre)
+    fig.canvas.mpl_connect('draw_event', on_draw)
+    fig.canvas.draw()
+
+    assert pre_positions == draw_positions
+
+
+def test_pre_draw_event_inset_axes_geometry_finalized():
+    from mpl_toolkits.axes_grid1.inset_locator import inset_axes as make_inset
+
+    fig, ax = plt.subplots(constrained_layout=True)
+    ax.plot([1, 2, 3], [1, 4, 2])
+    inset = make_inset(ax, width='30%', height='30%', loc='upper right')
+    inset.plot([1, 2, 3], [3, 1, 2])
+
+    positions = {}
+
+    def on_pre(event):
+        positions['pre'] = inset.get_position().bounds
+
+    def on_draw(event):
+        positions['draw'] = inset.get_position().bounds
+
+    fig.canvas.mpl_connect('pre_draw_event', on_pre)
+    fig.canvas.mpl_connect('draw_event', on_draw)
+    fig.canvas.draw()
+
+    assert positions['pre'] == positions['draw']
diff --git a/lib/matplotlib/typing.py b/lib/matplotlib/typing.py
@@ -144,7 +144,7 @@
     "key_release_event"
 ]
 
-DrawEventType: TypeAlias = Literal["draw_event"]
+DrawEventType: TypeAlias = Literal["draw_event", "pre_draw_event"]
 PickEventType: TypeAlias = Literal["pick_event"]
 ResizeEventType: TypeAlias = Literal["resize_event"]
 CloseEventType: TypeAlias = Literal["close_event"]