diff --git a/.github/workflows/check.yaml b/.github/workflows/check.yaml
index 250c9b9..61c26e8 100644
--- a/.github/workflows/check.yaml
+++ b/.github/workflows/check.yaml
@@ -19,6 +19,8 @@ jobs:
       fail-fast: false
       matrix:
         env:
+          - "3.14t"
+          - "3.14"
           - "3.13"
           - "3.12"
           - "3.11"
@@ -38,9 +40,9 @@ jobs:
           cache-dependency-glob: "pyproject.toml"
           github-token: ${{ secrets.GITHUB_TOKEN }}
       - name: Install tox
-        run: uv tool install --python-preference only-managed --python 3.13 tox --with tox-uv
+        run: uv tool install --python-preference only-managed --python 3.14 tox --with tox-uv
       - name: Install Python
-        if: startsWith(matrix.env, '3.') && matrix.env != '3.13'
+        if: startsWith(matrix.env, '3.') && matrix.env != '3.14'
         run: uv python install --python-preference only-managed ${{ matrix.env }}
       - name: Setup test suite
         run: tox run -vv --notest --skip-missing-interpreters false -e ${{ matrix.env }}
diff --git a/.github/workflows/release.yaml b/.github/workflows/release.yaml
index a4c4f2f..f773e02 100644
--- a/.github/workflows/release.yaml
+++ b/.github/workflows/release.yaml
@@ -20,7 +20,7 @@ jobs:
           cache-dependency-glob: "pyproject.toml"
           github-token: ${{ secrets.GITHUB_TOKEN }}
       - name: Build package
-        run: uv build --python 3.13 --python-preference only-managed --sdist --wheel . --out-dir dist
+        run: uv build --python 3.14 --python-preference only-managed --sdist --wheel . --out-dir dist
       - name: Store the distribution packages
         uses: actions/upload-artifact@v4
         with:
diff --git a/.pre-commit-config.yaml b/.pre-commit-config.yaml
index 1e2b624..73f64b7 100644
--- a/.pre-commit-config.yaml
+++ b/.pre-commit-config.yaml
@@ -20,11 +20,11 @@ repos:
       - id: tox-ini-fmt
         args: ["-p", "fix"]
   - repo: https://github.com/tox-dev/pyproject-fmt
-    rev: "v2.7.0"
+    rev: "v2.8.0"
     hooks:
       - id: pyproject-fmt
   - repo: https://github.com/astral-sh/ruff-pre-commit
-    rev: "v0.13.3"
+    rev: "v0.14.0"
     hooks:
       - id: ruff-format
       - id: ruff
@@ -34,8 +34,8 @@ repos:
     hooks:
       - id: prettier
         additional_dependencies:
-          - prettier@3.5.1
-          - "@prettier/plugin-xml@3.4.1"
+          - prettier@3.6.2
+          - "@prettier/plugin-xml@3.4.2"
   - repo: meta
     hooks:
       - id: check-hooks-apply
diff --git a/README.md b/README.md
index 384e226..db11c3d 100644
--- a/README.md
+++ b/README.md
@@ -64,7 +64,8 @@ The following configuration options are accepted:
   `True`, add stub documentation for undocumented parameters to be able to add type info.
 - `always_use_bars_union ` (default: `False`): If `True`, display Union's using the | operator described in PEP 604.
   (e.g `X` | `Y` or `int` | `None`). If `False`, Unions will display with the typing in brackets. (e.g. `Union[X, Y]`
-  or `Optional[int]`)
+  or `Optional[int]`). Note that on 3.14 and later this will always be `True` and not configurable due the interpreter
+  no longer differentiating between the two types, and we have no way to determine what the user used.
 - `typehints_document_rtype` (default: `True`): If `False`, never add an `:rtype:` directive. If `True`, add the
   `:rtype:` directive if no existing `:rtype:` is found.
 - `typehints_document_rtype_none` (default: `True`): If `False`, never add an `:rtype: None` directive. If `True`, add the `:rtype: None`.
@@ -74,7 +75,6 @@ The following configuration options are accepted:
   [napoleon_use_rtype](https://www.sphinx-doc.org/en/master/usage/extensions/napoleon.html#confval-napoleon_use_rtype)
   to avoid generation of duplicate or redundant return type information.
 - `typehints_defaults` (default: `None`): If `None`, defaults are not added. Otherwise, adds a default annotation:
-
   - `'comma'` adds it after the type, changing Sphinx’ default look to “**param** (_int_, default: `1`) -- text”.
   - `'braces'` adds `(default: ...)` after the type (useful for numpydoc like styles).
   - `'braces-after'` adds `(default: ...)` at the end of the parameter documentation text instead.
diff --git a/pyproject.toml b/pyproject.toml
index 37105b9..206a6cb 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -1,7 +1,7 @@
 [build-system]
 build-backend = "hatchling.build"
 requires = [
-  "hatch-vcs>=0.4",
+  "hatch-vcs>=0.5",
   "hatchling>=1.27",
 ]
 
@@ -40,20 +40,20 @@ dynamic = [
   "version",
 ]
 dependencies = [
-  "sphinx>=8.2",
+  "sphinx>=8.2.3",
 ]
 optional-dependencies.docs = [
-  "furo>=2024.8.6",
+  "furo>=2025.9.25",
 ]
 optional-dependencies.testing = [
   "covdefaults>=2.3",
-  "coverage>=7.6.12",
-  "defusedxml>=0.7.1",         # required by sphinx.testing
-  "diff-cover>=9.2.3",
-  "pytest>=8.3.4",
-  "pytest-cov>=6",
-  "sphobjinv>=2.3.1.2",
-  "typing-extensions>=4.12.2",
+  "coverage>=7.10.7",
+  "defusedxml>=0.7.1",       # required by sphinx.testing
+  "diff-cover>=9.7.1",
+  "pytest>=8.4.2",
+  "pytest-cov>=7",
+  "sphobjinv>=2.3.1.3",
+  "typing-extensions>=4.15",
 ]
 urls.Changelog = "https://github.com/tox-dev/sphinx-autodoc-typehints/releases"
 urls.Homepage = "https://github.com/tox-dev/sphinx-autodoc-typehints"
diff --git a/src/sphinx_autodoc_typehints/__init__.py b/src/sphinx_autodoc_typehints/__init__.py
index c547569..537add4 100644
--- a/src/sphinx_autodoc_typehints/__init__.py
+++ b/src/sphinx_autodoc_typehints/__init__.py
@@ -36,7 +36,17 @@
     from sphinx.ext.autodoc import Options
 
 _LOGGER = logging.getLogger(__name__)
-_PYDATA_ANNOTS_TYPING = {"Any", "AnyStr", "Callable", "ClassVar", "Literal", "NoReturn", "Optional", "Tuple", "Union"}
+_PYDATA_ANNOTS_TYPING = {
+    "Any",
+    "AnyStr",
+    "Callable",
+    "ClassVar",
+    "Literal",
+    "NoReturn",
+    "Optional",
+    "Tuple",
+    *({"Union"} if sys.version_info < (3, 14) else set()),
+}
 _PYDATA_ANNOTS_TYPES = {
     *("AsyncGeneratorType", "BuiltinFunctionType", "BuiltinMethodType"),
     *("CellType", "ClassMethodDescriptorType", "CoroutineType"),
@@ -246,8 +256,10 @@ def format_annotation(annotation: Any, config: Config, *, short_literals: bool =
     formatted_args: str | None = ""
 
     always_use_bars_union: bool = getattr(config, "always_use_bars_union", True)
-    is_bars_union = full_name == "types.UnionType" or (
-        always_use_bars_union and type(annotation).__qualname__ == "_UnionGenericAlias"
+    is_bars_union = (
+        (sys.version_info >= (3, 14) and full_name == "typing.Union")
+        or full_name == "types.UnionType"
+        or (always_use_bars_union and type(annotation).__qualname__ == "_UnionGenericAlias")
     )
     if is_bars_union:
         full_name = ""
@@ -588,7 +600,7 @@ def _one_child(module: Module) -> stmt | None:
         return {}
 
     try:
-        type_comment = obj_ast.type_comment
+        type_comment = obj_ast.type_comment  # type: ignore[attr-defined]
     except AttributeError:
         return {}
 
@@ -610,7 +622,7 @@ def _one_child(module: Module) -> stmt | None:
     if comment_returns:
         rv["return"] = comment_returns
 
-    args = load_args(obj_ast)
+    args = load_args(obj_ast)  # type: ignore[arg-type]
     comment_args = split_type_comment_args(comment_args_str)
     is_inline = len(comment_args) == 1 and comment_args[0] == "..."
     if not is_inline:
diff --git a/tests/test_integration.py b/tests/test_integration.py
index 02369f8..4bd3904 100644
--- a/tests/test_integration.py
+++ b/tests/test_integration.py
@@ -92,7 +92,7 @@ class mod.Class(x, y, z=None)
 
       * **y** ("int") -- bar
 
-      * **z** ("Optional"["str"]) -- baz
+      * **z** ("str" | "None") -- baz
 
    class InnerClass
 
@@ -117,7 +117,7 @@ class InnerClass
 
          * **y** ("int") -- bar
 
-         * **z** ("Optional"["str"]) -- baz
+         * **z** ("str" | "None") -- baz
 
       Return type:
          "str"
@@ -131,7 +131,7 @@ class InnerClass
 
          * **y** ("int") -- bar
 
-         * **z** ("Optional"["str"]) -- baz
+         * **z** ("str" | "None") -- baz
 
       Return type:
          "str"
@@ -149,7 +149,7 @@ class InnerClass
 
          * **y** ("int") -- bar
 
-         * **z** ("Optional"["str"]) -- baz
+         * **z** ("str" | "None") -- baz
 
       Return type:
          "str"
@@ -284,7 +284,7 @@ def __init__(self, message: str) -> None:
 
       * **y** ("int") -- bar
 
-      * **z_** ("Optional"["str"]) -- baz
+      * **z_** ("str" | "None") -- baz
 
    Returns:
       something
@@ -471,7 +471,7 @@ def method_without_typehint(self, x):  # noqa: ANN001, ANN201, ARG002, PLR6301
    Function docstring.
 
    Parameters:
-      * **x** ("Union"["str", "bytes", "None"]) -- foo
+      * **x** ("str" | "bytes" | "None") -- foo
 
       * **y** ("str") -- bar
 
@@ -502,7 +502,7 @@ class mod.ClassWithTypehintsNotInline(x=None)
    Class docstring.
 
    Parameters:
-      **x** ("Optional"["Callable"[["int", "bytes"], "int"]]) -- foo
+      **x** ("Callable"[["int", "bytes"], "int"] | "None") -- foo
 
    foo(x=1)
 
@@ -519,8 +519,7 @@ class mod.ClassWithTypehintsNotInline(x=None)
       Method docstring.
 
       Parameters:
-         **x** ("Optional"["Callable"[["int", "bytes"], "int"]]) --
-         foo
+         **x** ("Callable"[["int", "bytes"], "int"] | "None") -- foo
 
       Return type:
          "ClassWithTypehintsNotInline"
@@ -666,9 +665,9 @@ def func_with_overload(a: str, b: str) -> None: ...
    they must both have the same type.
 
    Parameters:
-      * **a** ("Union"["int", "str"]) -- The first thing
+      * **a** ("int" | "str") -- The first thing
 
-      * **b** ("Union"["int", "str"]) -- The second thing
+      * **b** ("int" | "str") -- The second thing
 
    Return type:
       "None"
@@ -747,7 +746,7 @@ class mod.TestClassAttributeDocs
 
    A class
 
-   code: "Optional"["CodeType"]
+   code: "CodeType" | "None"
 
       An attribute
 """,
@@ -1547,6 +1546,7 @@ def test_integration(
     (Path(app.srcdir) / "index.rst").write_text(template.format(val.__name__))
     app.config.__dict__.update(configs[conf_run])
     app.config.__dict__.update(val.OPTIONS)
+    app.config.always_use_bars_union = True
     monkeypatch.setitem(sys.modules, "mod", sys.modules[__name__])
     app.build()
     assert "build succeeded" in status.getvalue()  # Build succeeded
diff --git a/tests/test_integration_autodoc_type_aliases.py b/tests/test_integration_autodoc_type_aliases.py
index f964042..5ee1fa4 100644
--- a/tests/test_integration_autodoc_type_aliases.py
+++ b/tests/test_integration_autodoc_type_aliases.py
@@ -97,13 +97,13 @@ def g(s: AliasedClass) -> AliasedClass:
 
 
 @expected(
-    """\
+    f"""\
 mod.function(x, y)
 
    Function docstring.
 
    Parameters:
-      * **x** ("Optional"[Array]) -- foo
+      * **x** ({'Array | "None"' if sys.version_info >= (3, 14) else '"Optional"[Array]'}) -- foo
 
       * **y** ("Schema") -- boo
 
diff --git a/tests/test_sphinx_autodoc_typehints.py b/tests/test_sphinx_autodoc_typehints.py
index c0963c2..097c0dc 100644
--- a/tests/test_sphinx_autodoc_typehints.py
+++ b/tests/test_sphinx_autodoc_typehints.py
@@ -181,7 +181,7 @@ def test_parse_annotation(annotation: Any, module: str, class_name: str, args: t
     pytest.param(Type[A], rf":py:class:`~typing.Type`\ \[:py:class:`~{__name__}.A`]", id="typing-A"),
     pytest.param(Any, ":py:data:`~typing.Any`", id="Any"),
     pytest.param(AnyStr, ":py:data:`~typing.AnyStr`", id="AnyStr"),
-    pytest.param(Generic[T], r":py:class:`~typing.Generic`\ \[:py:class:`~typing.TypeVar`\ \(``T``)]", id="Generic"),
+    pytest.param(Generic[T], r":py:class:`~typing.Generic`\ \[:py:class:`~typing.TypeVar`\ \(``T``)]", id="Generic"),  # type: ignore[index]
     pytest.param(Mapping, ":py:class:`~collections.abc.Mapping`", id="Mapping"),
     pytest.param(
         Mapping[T, int],  # type: ignore[valid-type]
@@ -244,37 +244,63 @@ def test_parse_annotation(annotation: Any, module: str, class_name: str, args: t
         r":py:data:`~typing.Tuple`\ \[:py:class:`str`, :py:data:`...<Ellipsis>`]",
         id="Tuple-str-Ellipsis",
     ),
-    pytest.param(Union, ":py:data:`~typing.Union`", id="Union"),
+    pytest.param(Union, "" if sys.version_info >= (3, 14) else ":py:data:`~typing.Union`", id="Union"),
     pytest.param(
         Union[str, bool],
-        r":py:data:`~typing.Union`\ \[:py:class:`str`, :py:class:`bool`]",
+        ":py:class:`str` | :py:class:`bool`"
+        if sys.version_info >= (3, 14)
+        else r":py:data:`~typing.Union`\ \[:py:class:`str`, :py:class:`bool`]",
         id="Union-str-bool",
     ),
     pytest.param(
         Union[str, bool, None],
-        r":py:data:`~typing.Union`\ \[:py:class:`str`, :py:class:`bool`, :py:obj:`None`]",
+        ":py:class:`str` | :py:class:`bool` | :py:obj:`None`"
+        if sys.version_info >= (3, 14)
+        else r":py:data:`~typing.Union`\ \[:py:class:`str`, :py:class:`bool`, :py:obj:`None`]",
         id="Union-str-bool-None",
     ),
     pytest.param(
         Union[str, Any],
-        r":py:data:`~typing.Union`\ \[:py:class:`str`, :py:data:`~typing.Any`]",
+        ":py:class:`str` | :py:data:`~typing.Any`"
+        if sys.version_info >= (3, 14)
+        else r":py:data:`~typing.Union`\ \[:py:class:`str`, :py:data:`~typing.Any`]",
         id="Union-str-Any",
     ),
     pytest.param(
         Optional[str],
-        r":py:data:`~typing.Optional`\ \[:py:class:`str`]",
+        ":py:class:`str` | :py:obj:`None`"
+        if sys.version_info >= (3, 14)
+        else r":py:data:`~typing.Optional`\ \[:py:class:`str`]",
         id="Optional-str",
     ),
     pytest.param(
         Union[str, None],
-        r":py:data:`~typing.Optional`\ \[:py:class:`str`]",
+        ":py:class:`str` | :py:obj:`None`"
+        if sys.version_info >= (3, 14)
+        else r":py:data:`~typing.Optional`\ \[:py:class:`str`]",
         id="Optional-str-None",
     ),
     pytest.param(
         Optional[str | bool],
-        r":py:data:`~typing.Union`\ \[:py:class:`str`, :py:class:`bool`, :py:obj:`None`]",
+        ":py:class:`str` | :py:class:`bool` | :py:obj:`None`"
+        if sys.version_info >= (3, 14)
+        else r":py:data:`~typing.Union`\ \[:py:class:`str`, :py:class:`bool`, :py:obj:`None`]",
         id="Optional-Union-str-bool",
     ),
+    pytest.param(
+        RecList,
+        ":py:class:`int` | :py:class:`~typing.List`\\ \\[RecList]"
+        if sys.version_info >= (3, 14)
+        else r":py:data:`~typing.Union`\ \[:py:class:`int`, :py:class:`~typing.List`\ \[RecList]]",
+        id="RecList",
+    ),
+    pytest.param(
+        MutualRecA,
+        ":py:class:`bool` | :py:class:`~typing.List`\\ \\[MutualRecB]"
+        if sys.version_info >= (3, 14)
+        else r":py:data:`~typing.Union`\ \[:py:class:`bool`, :py:class:`~typing.List`\ \[MutualRecB]]",
+        id="MutualRecA",
+    ),
     pytest.param(Callable, ":py:class:`~collections.abc.Callable`", id="Callable"),
     pytest.param(
         Callable[..., int],
@@ -359,14 +385,6 @@ def test_parse_annotation(annotation: Any, module: str, class_name: str, args: t
         r":py:data:`~typing.Tuple`\ \[:py:class:`int`, :py:data:`...<Ellipsis>`]",
         id="Tuple-p-Ellipsis",
     ),
-    pytest.param(
-        RecList, r":py:data:`~typing.Union`\ \[:py:class:`int`, :py:class:`~typing.List`\ \[RecList]]", id="RecList"
-    ),
-    pytest.param(
-        MutualRecA,
-        r":py:data:`~typing.Union`\ \[:py:class:`bool`, :py:class:`~typing.List`\ \[MutualRecB]]",
-        id="MutualRecA",
-    ),
 ]
 
 
@@ -418,7 +436,9 @@ def test_format_annotation(inv: Inventory, annotation: Any, expected_result: str
         assert format_annotation(annotation, conf) == expected_result
 
     # Test for the correct role (class vs data) using the official Sphinx inventory
-    if any(modname in expected_result for modname in ("typing", "types")):
+    if any(modname in expected_result for modname in ("typing", "types")) and not (
+        sys.version_info >= (3, 14) and isinstance(annotation, Union)
+    ):
         m = re.match(r"^:py:(?P<role>class|data|func):`~(?P<name>[^`]+)`", result)
         assert m, "No match"
         name = m.group("name")
diff --git a/tox.ini b/tox.ini
index 87924c5..e7e0a31 100644
--- a/tox.ini
+++ b/tox.ini
@@ -1,13 +1,15 @@
 [tox]
 requires =
-    tox>=4.24.1
-    tox-uv>=1.24
+    tox>=4.30.2
+    tox-uv>=1.28
 env_list =
     fix
+    3.14
     3.13
     3.12
     3.11
     type
+    3.14t
     pkg_meta
 skip_missing_interpreters = true
 
@@ -37,15 +39,15 @@ commands =
 description = format the code base to adhere to our styles, and complain about what we cannot do automatically
 skip_install = true
 deps =
-    pre-commit-uv>=4.1.4
+    pre-commit-uv>=4.1.5
 commands =
     pre-commit run --all-files --show-diff-on-failure
 
 [testenv:type]
 description = run type check on code base
 deps =
-    mypy==1.15
-    types-docutils>=0.21.0.20250604
+    mypy==1.18.2
+    types-docutils>=0.22.2.20250924
 commands =
     mypy src
     mypy tests
@@ -54,9 +56,9 @@ commands =
 description = check that the long description is valid
 skip_install = true
 deps =
-    check-wheel-contents>=0.6.1
-    twine>=6.1
-    uv>=0.6.1
+    check-wheel-contents>=0.6.3
+    twine>=6.2
+    uv>=0.8.22
 commands =
     uv build --sdist --wheel --out-dir {env_tmp_dir} .
     twine check {env_tmp_dir}{/}*