diff --git a/IPython/core/pylabtools.py b/IPython/core/pylabtools.py
index 1f5a11f37e..4287834418 100644
--- a/IPython/core/pylabtools.py
+++ b/IPython/core/pylabtools.py
@@ -345,8 +345,10 @@ def find_gui_and_backend(gui=None, gui_select=None):
             backend = matplotlib.rcParamsOrig["backend"]
             backend, gui = backend_registry.resolve_backend(backend)
         else:
+            gui = _convert_gui_to_matplotlib(gui)
             backend, gui = backend_registry.resolve_gui_or_backend(gui)
 
+        gui = _convert_gui_from_matplotlib(gui)
         return gui, backend
 
     # Fallback to previous behaviour (Matplotlib < 3.9)
@@ -509,10 +511,28 @@ def _list_matplotlib_backends_and_gui_loops() -> list[str]:
     if _matplotlib_manages_backends():
         from matplotlib.backends.registry import backend_registry
 
-        ret = backend_registry.list_all() + backend_registry.list_gui_frameworks()
+        ret = backend_registry.list_all() + [
+            _convert_gui_from_matplotlib(gui)
+            for gui in backend_registry.list_gui_frameworks()
+        ]
     else:
         from IPython.core import pylabtools
 
         ret = list(pylabtools.backends.keys())
 
     return sorted(["auto"] + ret)
+
+
+# Matplotlib and IPython do not always use the same gui framework name.
+# Always use the approprate one of these conversion functions when passing a
+# gui framework name to/from Matplotlib.
+def _convert_gui_to_matplotlib(gui: str | None) -> str | None:
+    if gui and gui.lower() == "osx":
+        return "macosx"
+    return gui
+
+
+def _convert_gui_from_matplotlib(gui: str | None) -> str | None:
+    if gui and gui.lower() == "macosx":
+        return "osx"
+    return gui
diff --git a/IPython/core/tests/test_pylabtools.py b/IPython/core/tests/test_pylabtools.py
index 4099f04044..6bddb34807 100644
--- a/IPython/core/tests/test_pylabtools.py
+++ b/IPython/core/tests/test_pylabtools.py
@@ -276,11 +276,11 @@ def test_figure_no_canvas():
         # name is gui
         ("gtk3", "gtk3", "gtk3agg"),
         ("gtk4", "gtk4", "gtk4agg"),
-        ("headless", "headless", "agg"),
+        ("headless", None, "agg"),
         ("osx", "osx", "macosx"),
         ("qt", "qt", "qtagg"),
         ("qt5", "qt5", "qt5agg"),
-        ("qt6", "qt6", "qt6agg"),
+        ("qt6", "qt6", "qtagg"),
         ("tk", "tk", "tkagg"),
         ("wx", "wx", "wxagg"),
         # name is backend
@@ -301,8 +301,6 @@ def test_figure_no_canvas():
         ("qtcairo", "qt", "qtcairo"),
         ("qt5agg", "qt5", "qt5agg"),
         ("qt5cairo", "qt5", "qt5cairo"),
-        ("qt6agg", "qt", "qt6agg"),
-        ("qt6cairo", "qt", "qt6cairo"),
         ("tkagg", "tk", "tkagg"),
         ("tkcairo", "tk", "tkcairo"),
         ("webagg", "webagg", "webagg"),