diff --git a/altair/__init__.py b/altair/__init__.py
index 3b49f05d4..d9adb730f 100644
--- a/altair/__init__.py
+++ b/altair/__init__.py
@@ -674,7 +674,7 @@ def __getattr__(name: str) -> _Any:
             alternative="altair.theme",
             stacklevel=3,
         )
-        return theme.themes
+        return theme._themes
     else:
         msg = f"module {__name__!r} has no attribute {name!r}"
         raise AttributeError(msg)
diff --git a/altair/theme.py b/altair/theme.py
index ce0d7ba31..feacc1a91 100644
--- a/altair/theme.py
+++ b/altair/theme.py
@@ -78,7 +78,7 @@
     ViewBackgroundKwds,
     ViewConfigKwds,
 )
-from altair.vegalite.v5.theme import themes
+from altair.vegalite.v5.theme import themes as _themes
 
 if TYPE_CHECKING:
     import sys
@@ -174,7 +174,6 @@
     "names",
     "options",
     "register",
-    "themes",
     "unregister",
 ]
 
@@ -238,9 +237,9 @@ def custom_theme() -> theme.ThemeConfig:
     # HACK: See for `LiteralString` requirement in `name`
     # https://github.com/vega/altair/pull/3526#discussion_r1743350127
     def decorate(func: Plugin[ThemeConfig], /) -> Plugin[ThemeConfig]:
-        themes.register(name, func)
+        _themes.register(name, func)
         if enable:
-            themes.enable(name)
+            _themes.enable(name)
 
         @_wraps(func)
         def wrapper(*args: P.args, **kwargs: P.kwargs) -> ThemeConfig:
@@ -258,14 +257,14 @@ def unregister(name: LiteralString) -> Plugin[ThemeConfig]:
     Parameters
     ----------
     name
-        Unique name assigned in ``alt.theme.themes``.
+        Unique name assigned during ``alt.theme.register``.
 
     Raises
     ------
     TypeError
         When ``name`` has not been registered.
     """
-    plugin = themes.register(name, None)
+    plugin = _themes.register(name, None)
     if plugin is None:
         msg = (
             f"Found no theme named {name!r} in registry.\n"
@@ -277,9 +276,9 @@ def unregister(name: LiteralString) -> Plugin[ThemeConfig]:
         return plugin
 
 
-enable = themes.enable
-get = themes.get
-names = themes.names
+enable = _themes.enable
+get = _themes.get
+names = _themes.names
 active: str
 """Return the name of the currently active theme."""
 options: dict[str, Any]
@@ -296,9 +295,9 @@ def __getattr__(name: Literal["active"]) -> str: ...  # type: ignore[misc]
 def __getattr__(name: Literal["options"]) -> dict[str, Any]: ...  # type: ignore[misc]
 def __getattr__(name: str) -> Any:
     if name == "active":
-        return themes.active
+        return _themes.active
     elif name == "options":
-        return themes.options
+        return _themes.options
     else:
         msg = f"module {__name__!r} has no attribute {name!r}"
         raise AttributeError(msg)
diff --git a/doc/user_guide/api.rst b/doc/user_guide/api.rst
index 0cb91f6ae..d3c08f547 100644
--- a/doc/user_guide/api.rst
+++ b/doc/user_guide/api.rst
@@ -186,7 +186,6 @@ Theme
    names
    options
    register
-   themes
    unregister
    ThemeConfig
    AreaConfigKwds
diff --git a/tests/utils/test_deprecation.py b/tests/utils/test_deprecation.py
index cbc13dc5d..d1410f13c 100644
--- a/tests/utils/test_deprecation.py
+++ b/tests/utils/test_deprecation.py
@@ -58,4 +58,4 @@ def test_deprecated_import():
 
     with catch_warnings():
         filterwarnings("ignore", category=AltairDeprecationWarning)
-        assert alt.themes == alt.theme.themes
+        assert alt.themes == alt.theme._themes
diff --git a/tests/vegalite/test_common.py b/tests/vegalite/test_common.py
index 69c173b97..0ea5b049b 100644
--- a/tests/vegalite/test_common.py
+++ b/tests/vegalite/test_common.py
@@ -20,9 +20,9 @@ def basic_spec():
 
 
 def make_final_spec(alt, basic_spec):
-    from altair.theme import themes
+    from altair.theme import _themes
 
-    theme = themes.get()
+    theme = _themes.get()
     assert theme
     spec = theme()
     spec.update(basic_spec)
@@ -70,12 +70,12 @@ def test_basic_chart_from_dict(alt, basic_spec):
 
 @pytest.mark.parametrize("alt", [v5])
 def test_theme_enable(alt, basic_spec):
-    from altair.theme import themes
+    from altair.theme import _themes
 
-    active_theme = themes.active
+    active_theme = _themes.active
 
     try:
-        themes.enable("none")
+        _themes.enable("none")
 
         chart = alt.Chart.from_dict(basic_spec)
         dct = chart.to_dict()
@@ -88,7 +88,7 @@ def test_theme_enable(alt, basic_spec):
         assert dct == basic_spec
     finally:
         # reset the theme to its initial value
-        themes.enable(active_theme)  # pyright: ignore[reportArgumentType]
+        _themes.enable(active_theme)  # pyright: ignore[reportArgumentType]
 
 
 @pytest.mark.parametrize("alt", [v5])
diff --git a/tests/vegalite/v5/test_theme.py b/tests/vegalite/v5/test_theme.py
index 484d6d252..da7c134ba 100644
--- a/tests/vegalite/v5/test_theme.py
+++ b/tests/vegalite/v5/test_theme.py
@@ -78,8 +78,8 @@ def test_theme_register_decorator() -> None:
     def custom_theme() -> ThemeConfig:
         return {"height": 400, "width": 700}
 
-    assert theme.themes.active == "unique name" == theme.active
-    registered = theme.themes.get()
+    assert theme._themes.active == "unique name" == theme.active
+    registered = theme._themes.get()
     assert registered is not None
     assert registered == theme.get()
     assert registered() == {"height": 400, "width": 700} == custom_theme()
@@ -93,7 +93,7 @@ def custom_theme() -> ThemeConfig:
     assert theme.active == "big square"
     fn = theme.unregister("big square")
     assert fn() == custom_theme()
-    assert theme.active == theme.themes.active
+    assert theme.active == theme._themes.active
     # BUG: https://github.com/vega/altair/issues/3619
     # assert theme.active != "big square"