diff --git a/pandas/_typing.py b/pandas/_typing.py
index 12d23786c3387..906b77319406f 100644
--- a/pandas/_typing.py
+++ b/pandas/_typing.py
@@ -101,12 +101,6 @@
 ]
 Timezone = Union[str, tzinfo]
 
-# FrameOrSeriesUnion  means either a DataFrame or a Series. E.g.
-# `def func(a: FrameOrSeriesUnion) -> FrameOrSeriesUnion: ...` means that if a Series
-# is passed in, either a Series or DataFrame is returned, and if a DataFrame is passed
-# in, either a DataFrame or a Series is returned.
-FrameOrSeriesUnion = Union["DataFrame", "Series"]
-
 # FrameOrSeries is stricter and ensures that the same subclass of NDFrame always is
 # used. E.g. `def func(a: FrameOrSeries) -> FrameOrSeries: ...` means that if a
 # Series is passed into a function, a Series is always returned and if a DataFrame is
diff --git a/pandas/core/algorithms.py b/pandas/core/algorithms.py
index f26cf113f7d5e..f727b7b15c8b1 100644
--- a/pandas/core/algorithms.py
+++ b/pandas/core/algorithms.py
@@ -29,7 +29,6 @@
     AnyArrayLike,
     ArrayLike,
     DtypeObj,
-    FrameOrSeriesUnion,
     Scalar,
 )
 from pandas.util._decorators import doc
@@ -1211,7 +1210,7 @@ def __init__(self, obj, n: int, keep: str):
         if self.keep not in ("first", "last", "all"):
             raise ValueError('keep must be either "first", "last" or "all"')
 
-    def compute(self, method: str) -> FrameOrSeriesUnion:
+    def compute(self, method: str) -> DataFrame | Series:
         raise NotImplementedError
 
     def nlargest(self):
diff --git a/pandas/core/apply.py b/pandas/core/apply.py
index 388c1881afed7..f2e60f43d2a54 100644
--- a/pandas/core/apply.py
+++ b/pandas/core/apply.py
@@ -25,7 +25,6 @@
     AggObjType,
     Axis,
     FrameOrSeries,
-    FrameOrSeriesUnion,
 )
 from pandas.util._decorators import cache_readonly
 
@@ -137,10 +136,10 @@ def f(x):
         self.f: AggFuncType = f
 
     @abc.abstractmethod
-    def apply(self) -> FrameOrSeriesUnion:
+    def apply(self) -> DataFrame | Series:
         pass
 
-    def agg(self) -> FrameOrSeriesUnion | None:
+    def agg(self) -> DataFrame | Series | None:
         """
         Provide an implementation for the aggregators.
 
@@ -171,7 +170,7 @@ def agg(self) -> FrameOrSeriesUnion | None:
         # caller can react
         return None
 
-    def transform(self) -> FrameOrSeriesUnion:
+    def transform(self) -> DataFrame | Series:
         """
         Transform a DataFrame or Series.
 
@@ -252,7 +251,7 @@ def transform_dict_like(self, func):
 
         func = self.normalize_dictlike_arg("transform", obj, func)
 
-        results: dict[Hashable, FrameOrSeriesUnion] = {}
+        results: dict[Hashable, DataFrame | Series] = {}
         failed_names = []
         all_type_errors = True
         for name, how in func.items():
@@ -283,7 +282,7 @@ def transform_dict_like(self, func):
             )
         return concat(results, axis=1)
 
-    def transform_str_or_callable(self, func) -> FrameOrSeriesUnion:
+    def transform_str_or_callable(self, func) -> DataFrame | Series:
         """
         Compute transform in the case of a string or callable func
         """
@@ -305,7 +304,7 @@ def transform_str_or_callable(self, func) -> FrameOrSeriesUnion:
         except Exception:
             return func(obj, *args, **kwargs)
 
-    def agg_list_like(self) -> FrameOrSeriesUnion:
+    def agg_list_like(self) -> DataFrame | Series:
         """
         Compute aggregation in the case of a list-like argument.
 
@@ -399,7 +398,7 @@ def agg_list_like(self) -> FrameOrSeriesUnion:
             )
             return concatenated.reindex(full_ordered_index, copy=False)
 
-    def agg_dict_like(self) -> FrameOrSeriesUnion:
+    def agg_dict_like(self) -> DataFrame | Series:
         """
         Compute aggregation in the case of a dict-like argument.
 
@@ -467,7 +466,7 @@ def agg_dict_like(self) -> FrameOrSeriesUnion:
 
         return result
 
-    def apply_str(self) -> FrameOrSeriesUnion:
+    def apply_str(self) -> DataFrame | Series:
         """
         Compute apply in case of a string.
 
@@ -492,7 +491,7 @@ def apply_str(self) -> FrameOrSeriesUnion:
                 raise ValueError(f"Operation {f} does not support axis=1")
         return self._try_aggregate_string_function(obj, f, *self.args, **self.kwargs)
 
-    def apply_multiple(self) -> FrameOrSeriesUnion:
+    def apply_multiple(self) -> DataFrame | Series:
         """
         Compute apply in case of a list-like or dict-like.
 
@@ -504,7 +503,7 @@ def apply_multiple(self) -> FrameOrSeriesUnion:
         return self.obj.aggregate(self.f, self.axis, *self.args, **self.kwargs)
 
     def normalize_dictlike_arg(
-        self, how: str, obj: FrameOrSeriesUnion, func: AggFuncTypeDict
+        self, how: str, obj: DataFrame | Series, func: AggFuncTypeDict
     ) -> AggFuncTypeDict:
         """
         Handler for dict-like argument.
@@ -617,7 +616,7 @@ def series_generator(self) -> Iterator[Series]:
     @abc.abstractmethod
     def wrap_results_for_axis(
         self, results: ResType, res_index: Index
-    ) -> FrameOrSeriesUnion:
+    ) -> DataFrame | Series:
         pass
 
     # ---------------------------------------------------------------
@@ -638,7 +637,7 @@ def values(self):
     def dtypes(self) -> Series:
         return self.obj.dtypes
 
-    def apply(self) -> FrameOrSeriesUnion:
+    def apply(self) -> DataFrame | Series:
         """compute the results"""
         # dispatch to agg
         if is_list_like(self.f):
@@ -812,7 +811,7 @@ def apply_series_generator(self) -> tuple[ResType, Index]:
 
         return results, res_index
 
-    def wrap_results(self, results: ResType, res_index: Index) -> FrameOrSeriesUnion:
+    def wrap_results(self, results: ResType, res_index: Index) -> DataFrame | Series:
         from pandas import Series
 
         # see if we can infer the results
@@ -835,7 +834,7 @@ def wrap_results(self, results: ResType, res_index: Index) -> FrameOrSeriesUnion
 
         return result
 
-    def apply_str(self) -> FrameOrSeriesUnion:
+    def apply_str(self) -> DataFrame | Series:
         # Caller is responsible for checking isinstance(self.f, str)
         # TODO: GH#39993 - Avoid special-casing by replacing with lambda
         if self.f == "size":
@@ -866,7 +865,7 @@ def result_columns(self) -> Index:
 
     def wrap_results_for_axis(
         self, results: ResType, res_index: Index
-    ) -> FrameOrSeriesUnion:
+    ) -> DataFrame | Series:
         """return the results for the rows"""
 
         if self.result_type == "reduce":
@@ -949,9 +948,9 @@ def result_columns(self) -> Index:
 
     def wrap_results_for_axis(
         self, results: ResType, res_index: Index
-    ) -> FrameOrSeriesUnion:
+    ) -> DataFrame | Series:
         """return the results for the columns"""
-        result: FrameOrSeriesUnion
+        result: DataFrame | Series
 
         # we have requested to expand
         if self.result_type == "expand":
@@ -1005,7 +1004,7 @@ def __init__(
             kwargs=kwargs,
         )
 
-    def apply(self) -> FrameOrSeriesUnion:
+    def apply(self) -> DataFrame | Series:
         obj = self.obj
 
         if len(obj) == 0:
@@ -1056,7 +1055,7 @@ def apply_empty_result(self) -> Series:
             obj, method="apply"
         )
 
-    def apply_standard(self) -> FrameOrSeriesUnion:
+    def apply_standard(self) -> DataFrame | Series:
         f = self.f
         obj = self.obj
 
diff --git a/pandas/core/describe.py b/pandas/core/describe.py
index dfb18b2c40698..0fd7838ab5acc 100644
--- a/pandas/core/describe.py
+++ b/pandas/core/describe.py
@@ -22,7 +22,6 @@
 from pandas._libs.tslibs import Timestamp
 from pandas._typing import (
     FrameOrSeries,
-    FrameOrSeriesUnion,
     Hashable,
 )
 from pandas.util._validators import validate_percentile
@@ -107,12 +106,12 @@ class NDFrameDescriberAbstract(ABC):
         Whether to treat datetime dtypes as numeric.
     """
 
-    def __init__(self, obj: FrameOrSeriesUnion, datetime_is_numeric: bool):
+    def __init__(self, obj: DataFrame | Series, datetime_is_numeric: bool):
         self.obj = obj
         self.datetime_is_numeric = datetime_is_numeric
 
     @abstractmethod
-    def describe(self, percentiles: Sequence[float]) -> FrameOrSeriesUnion:
+    def describe(self, percentiles: Sequence[float]) -> DataFrame | Series:
         """Do describe either series or dataframe.
 
         Parameters
diff --git a/pandas/core/frame.py b/pandas/core/frame.py
index 91b9bdd564676..57b2e701fce35 100644
--- a/pandas/core/frame.py
+++ b/pandas/core/frame.py
@@ -58,7 +58,6 @@
     FillnaOptions,
     FloatFormatType,
     FormattersType,
-    FrameOrSeriesUnion,
     Frequency,
     IndexKeyFunc,
     IndexLabel,
@@ -1362,7 +1361,7 @@ def dot(self, other: Series) -> Series:
     def dot(self, other: DataFrame | Index | ArrayLike) -> DataFrame:
         ...
 
-    def dot(self, other: AnyArrayLike | FrameOrSeriesUnion) -> FrameOrSeriesUnion:
+    def dot(self, other: AnyArrayLike | DataFrame | Series) -> DataFrame | Series:
         """
         Compute the matrix multiplication between the DataFrame and other.
 
@@ -1478,13 +1477,13 @@ def __matmul__(self, other: Series) -> Series:
 
     @overload
     def __matmul__(
-        self, other: AnyArrayLike | FrameOrSeriesUnion
-    ) -> FrameOrSeriesUnion:
+        self, other: AnyArrayLike | DataFrame | Series
+    ) -> DataFrame | Series:
         ...
 
     def __matmul__(
-        self, other: AnyArrayLike | FrameOrSeriesUnion
-    ) -> FrameOrSeriesUnion:
+        self, other: AnyArrayLike | DataFrame | Series
+    ) -> DataFrame | Series:
         """
         Matrix multiplication using binary `@` operator in Python>=3.5.
         """
@@ -8401,8 +8400,8 @@ def _gotitem(
         self,
         key: IndexLabel,
         ndim: int,
-        subset: FrameOrSeriesUnion | None = None,
-    ) -> FrameOrSeriesUnion:
+        subset: DataFrame | Series | None = None,
+    ) -> DataFrame | Series:
         """
         Sub-classes to define. Return a sliced object.
 
@@ -8931,7 +8930,7 @@ def append(
 
     def join(
         self,
-        other: FrameOrSeriesUnion,
+        other: DataFrame | Series,
         on: IndexLabel | None = None,
         how: str = "left",
         lsuffix: str = "",
@@ -9061,7 +9060,7 @@ def join(
 
     def _join_compat(
         self,
-        other: FrameOrSeriesUnion,
+        other: DataFrame | Series,
         on: IndexLabel | None = None,
         how: str = "left",
         lsuffix: str = "",
@@ -9131,7 +9130,7 @@ def _join_compat(
     @Appender(_merge_doc, indents=2)
     def merge(
         self,
-        right: FrameOrSeriesUnion,
+        right: DataFrame | Series,
         how: str = "inner",
         on: IndexLabel | None = None,
         left_on: IndexLabel | None = None,
@@ -10724,7 +10723,7 @@ def _from_nested_dict(data) -> collections.defaultdict:
     return new_data
 
 
-def _reindex_for_setitem(value: FrameOrSeriesUnion, index: Index) -> ArrayLike:
+def _reindex_for_setitem(value: DataFrame | Series, index: Index) -> ArrayLike:
     # reindex if necessary
 
     if value.index.equals(index) or not len(index):
diff --git a/pandas/core/groupby/generic.py b/pandas/core/groupby/generic.py
index 69f992f840c7c..d50e921347f98 100644
--- a/pandas/core/groupby/generic.py
+++ b/pandas/core/groupby/generic.py
@@ -33,7 +33,6 @@
 from pandas._typing import (
     ArrayLike,
     FrameOrSeries,
-    FrameOrSeriesUnion,
     Manager2D,
 )
 from pandas.util._decorators import (
@@ -296,7 +295,7 @@ def _aggregate_multiple_funcs(self, arg) -> DataFrame:
 
             arg = zip(columns, arg)
 
-        results: dict[base.OutputKey, FrameOrSeriesUnion] = {}
+        results: dict[base.OutputKey, DataFrame | Series] = {}
         for idx, (name, func) in enumerate(arg):
 
             key = base.OutputKey(label=name, position=idx)
@@ -422,7 +421,7 @@ def _wrap_applied_output(
         keys: Index,
         values: list[Any] | None,
         not_indexed_same: bool = False,
-    ) -> FrameOrSeriesUnion:
+    ) -> DataFrame | Series:
         """
         Wrap the output of SeriesGroupBy.apply into the expected result.
 
@@ -1191,7 +1190,7 @@ def _wrap_applied_output_series(
         not_indexed_same: bool,
         first_not_none,
         key_index,
-    ) -> FrameOrSeriesUnion:
+    ) -> DataFrame | Series:
         # this is to silence a DeprecationWarning
         # TODO: Remove when default dtype of empty Series is object
         kwargs = first_not_none._construct_axes_dict()
diff --git a/pandas/core/groupby/groupby.py b/pandas/core/groupby/groupby.py
index f694dcce809ea..90a641a246eb2 100644
--- a/pandas/core/groupby/groupby.py
+++ b/pandas/core/groupby/groupby.py
@@ -45,7 +45,6 @@ class providing the base-class of operations.
     ArrayLike,
     F,
     FrameOrSeries,
-    FrameOrSeriesUnion,
     IndexLabel,
     Scalar,
     T,
@@ -728,7 +727,7 @@ def pipe(
     plot = property(GroupByPlot)
 
     @final
-    def get_group(self, name, obj=None) -> FrameOrSeriesUnion:
+    def get_group(self, name, obj=None) -> DataFrame | Series:
         """
         Construct DataFrame from group with provided name.
 
@@ -1267,8 +1266,8 @@ def f(g):
 
     @final
     def _python_apply_general(
-        self, f: F, data: FrameOrSeriesUnion
-    ) -> FrameOrSeriesUnion:
+        self, f: F, data: DataFrame | Series
+    ) -> DataFrame | Series:
         """
         Apply function f in python space
 
@@ -1786,7 +1785,7 @@ def sem(self, ddof: int = 1):
     @final
     @Substitution(name="groupby")
     @Appender(_common_see_also)
-    def size(self) -> FrameOrSeriesUnion:
+    def size(self) -> DataFrame | Series:
         """
         Compute group sizes.
 
diff --git a/pandas/core/reshape/concat.py b/pandas/core/reshape/concat.py
index ea34bc75b4e31..4952fd5582fdb 100644
--- a/pandas/core/reshape/concat.py
+++ b/pandas/core/reshape/concat.py
@@ -15,7 +15,6 @@
 
 import numpy as np
 
-from pandas._typing import FrameOrSeriesUnion
 from pandas.util._decorators import (
     cache_readonly,
     deprecate_nonkeyword_arguments,
@@ -83,7 +82,7 @@ def concat(
     verify_integrity: bool = False,
     sort: bool = False,
     copy: bool = True,
-) -> FrameOrSeriesUnion:
+) -> DataFrame | Series:
     ...
 
 
@@ -99,7 +98,7 @@ def concat(
     verify_integrity: bool = False,
     sort: bool = False,
     copy: bool = True,
-) -> FrameOrSeriesUnion:
+) -> DataFrame | Series:
     """
     Concatenate pandas objects along a particular axis with optional set logic
     along the other axes.
@@ -454,7 +453,7 @@ def __init__(
                     if self._is_frame and axis == 1:
                         name = 0
                     # mypy needs to know sample is not an NDFrame
-                    sample = cast("FrameOrSeriesUnion", sample)
+                    sample = cast("DataFrame | Series", sample)
                     obj = sample._constructor({name: obj})
 
                 self.objs.append(obj)
@@ -474,8 +473,8 @@ def __init__(
         self.new_axes = self._get_new_axes()
 
     def get_result(self):
-        cons: type[FrameOrSeriesUnion]
-        sample: FrameOrSeriesUnion
+        cons: type[DataFrame | Series]
+        sample: DataFrame | Series
 
         # series only
         if self._is_series:
diff --git a/pandas/core/reshape/pivot.py b/pandas/core/reshape/pivot.py
index 51556fda6da04..d96f2628088a5 100644
--- a/pandas/core/reshape/pivot.py
+++ b/pandas/core/reshape/pivot.py
@@ -14,7 +14,6 @@
     AggFuncType,
     AggFuncTypeBase,
     AggFuncTypeDict,
-    FrameOrSeriesUnion,
     IndexLabel,
 )
 from pandas.util._decorators import (
@@ -254,7 +253,7 @@ def __internal_pivot_table(
 
 
 def _add_margins(
-    table: FrameOrSeriesUnion,
+    table: DataFrame | Series,
     data,
     values,
     rows,
diff --git a/pandas/core/series.py b/pandas/core/series.py
index 59ea6710ea6cd..5173e98ab8136 100644
--- a/pandas/core/series.py
+++ b/pandas/core/series.py
@@ -39,7 +39,6 @@
     Dtype,
     DtypeObj,
     FillnaOptions,
-    FrameOrSeriesUnion,
     IndexKeyFunc,
     NpDtype,
     SingleManager,
@@ -3022,7 +3021,7 @@ def compare(
         align_axis: Axis = 1,
         keep_shape: bool = False,
         keep_equal: bool = False,
-    ) -> FrameOrSeriesUnion:
+    ) -> DataFrame | Series:
         return super().compare(
             other=other,
             align_axis=align_axis,
@@ -4178,7 +4177,7 @@ def aggregate(self, func=None, axis=0, *args, **kwargs):
     )
     def transform(
         self, func: AggFuncType, axis: Axis = 0, *args, **kwargs
-    ) -> FrameOrSeriesUnion:
+    ) -> DataFrame | Series:
         # Validate axis argument
         self._get_axis_number(axis)
         result = SeriesApply(
@@ -4192,7 +4191,7 @@ def apply(
         convert_dtype: bool = True,
         args: tuple[Any, ...] = (),
         **kwargs,
-    ) -> FrameOrSeriesUnion:
+    ) -> DataFrame | Series:
         """
         Invoke function on values of Series.
 
diff --git a/pandas/core/strings/accessor.py b/pandas/core/strings/accessor.py
index 323cb6bd9fedd..73317cc39c2af 100644
--- a/pandas/core/strings/accessor.py
+++ b/pandas/core/strings/accessor.py
@@ -13,10 +13,7 @@
 import numpy as np
 
 import pandas._libs.lib as lib
-from pandas._typing import (
-    DtypeObj,
-    FrameOrSeriesUnion,
-)
+from pandas._typing import DtypeObj
 from pandas.util._decorators import Appender
 
 from pandas.core.dtypes.common import (
@@ -39,7 +36,11 @@
 from pandas.core.base import NoNewAttributesMixin
 
 if TYPE_CHECKING:
-    from pandas import Index
+    from pandas import (
+        DataFrame,
+        Index,
+        Series,
+    )
 
 _shared_docs: dict[str, str] = {}
 _cpython_optimized_encoders = (
@@ -2314,7 +2315,7 @@ def findall(self, pat, flags=0):
     @forbid_nonstring_types(["bytes"])
     def extract(
         self, pat: str, flags: int = 0, expand: bool = True
-    ) -> FrameOrSeriesUnion | Index:
+    ) -> DataFrame | Series | Index:
         r"""
         Extract capture groups in the regex `pat` as columns in a DataFrame.
 
diff --git a/pandas/core/util/hashing.py b/pandas/core/util/hashing.py
index fb5002648b6a5..03a66225a846f 100644
--- a/pandas/core/util/hashing.py
+++ b/pandas/core/util/hashing.py
@@ -15,10 +15,7 @@
 import numpy as np
 
 from pandas._libs.hashing import hash_object_array
-from pandas._typing import (
-    ArrayLike,
-    FrameOrSeriesUnion,
-)
+from pandas._typing import ArrayLike
 
 from pandas.core.dtypes.common import (
     is_categorical_dtype,
@@ -34,6 +31,7 @@
 if TYPE_CHECKING:
     from pandas import (
         Categorical,
+        DataFrame,
         Index,
         MultiIndex,
         Series,
@@ -77,7 +75,7 @@ def combine_hash_arrays(arrays: Iterator[np.ndarray], num_items: int) -> np.ndar
 
 
 def hash_pandas_object(
-    obj: Index | FrameOrSeriesUnion,
+    obj: Index | DataFrame | Series,
     index: bool = True,
     encoding: str = "utf8",
     hash_key: str | None = _default_hash_key,
diff --git a/pandas/core/window/ewm.py b/pandas/core/window/ewm.py
index c1d532d94eb83..664089fa37b83 100644
--- a/pandas/core/window/ewm.py
+++ b/pandas/core/window/ewm.py
@@ -3,6 +3,7 @@
 import datetime
 from functools import partial
 from textwrap import dedent
+from typing import TYPE_CHECKING
 import warnings
 
 import numpy as np
@@ -12,9 +13,12 @@
 from pandas._typing import (
     Axis,
     FrameOrSeries,
-    FrameOrSeriesUnion,
     TimedeltaConvertibleTypes,
 )
+
+if TYPE_CHECKING:
+    from pandas import DataFrame, Series
+
 from pandas.compat.numpy import function as nv
 from pandas.util._decorators import doc
 
@@ -558,7 +562,7 @@ def var_func(values, begin, end, min_periods):
     )
     def cov(
         self,
-        other: FrameOrSeriesUnion | None = None,
+        other: DataFrame | Series | None = None,
         pairwise: bool | None = None,
         bias: bool = False,
         **kwargs,
@@ -625,7 +629,7 @@ def cov_func(x, y):
     )
     def corr(
         self,
-        other: FrameOrSeriesUnion | None = None,
+        other: DataFrame | Series | None = None,
         pairwise: bool | None = None,
         **kwargs,
     ):
@@ -761,7 +765,7 @@ def std(self, bias: bool = False, *args, **kwargs):
 
     def corr(
         self,
-        other: FrameOrSeriesUnion | None = None,
+        other: DataFrame | Series | None = None,
         pairwise: bool | None = None,
         **kwargs,
     ):
@@ -769,7 +773,7 @@ def corr(
 
     def cov(
         self,
-        other: FrameOrSeriesUnion | None = None,
+        other: DataFrame | Series | None = None,
         pairwise: bool | None = None,
         bias: bool = False,
         **kwargs,
diff --git a/pandas/core/window/expanding.py b/pandas/core/window/expanding.py
index 02cf31cad7b8d..eedb6930bad66 100644
--- a/pandas/core/window/expanding.py
+++ b/pandas/core/window/expanding.py
@@ -2,6 +2,7 @@
 
 from textwrap import dedent
 from typing import (
+    TYPE_CHECKING,
     Any,
     Callable,
 )
@@ -9,8 +10,11 @@
 from pandas._typing import (
     Axis,
     FrameOrSeries,
-    FrameOrSeriesUnion,
 )
+
+if TYPE_CHECKING:
+    from pandas import DataFrame, Series
+
 from pandas.compat.numpy import function as nv
 from pandas.util._decorators import doc
 
@@ -591,7 +595,7 @@ def quantile(
     )
     def cov(
         self,
-        other: FrameOrSeriesUnion | None = None,
+        other: DataFrame | Series | None = None,
         pairwise: bool | None = None,
         ddof: int = 1,
         **kwargs,
@@ -656,7 +660,7 @@ def cov(
     )
     def corr(
         self,
-        other: FrameOrSeriesUnion | None = None,
+        other: DataFrame | Series | None = None,
         pairwise: bool | None = None,
         ddof: int = 1,
         **kwargs,
diff --git a/pandas/core/window/rolling.py b/pandas/core/window/rolling.py
index 2d5f148a6437a..31951b3f29a82 100644
--- a/pandas/core/window/rolling.py
+++ b/pandas/core/window/rolling.py
@@ -28,7 +28,6 @@
     ArrayLike,
     Axis,
     FrameOrSeries,
-    FrameOrSeriesUnion,
 )
 from pandas.compat._optional import import_optional_dependency
 from pandas.compat.numpy import function as nv
@@ -408,7 +407,7 @@ def _apply_series(
 
     def _apply_blockwise(
         self, homogeneous_func: Callable[..., ArrayLike], name: str | None = None
-    ) -> FrameOrSeriesUnion:
+    ) -> DataFrame | Series:
         """
         Apply the given function to the DataFrame broken down into homogeneous
         sub-frames.
@@ -443,7 +442,7 @@ def hfunc2d(values: ArrayLike) -> ArrayLike:
 
     def _apply_tablewise(
         self, homogeneous_func: Callable[..., ArrayLike], name: str | None = None
-    ) -> FrameOrSeriesUnion:
+    ) -> DataFrame | Series:
         """
         Apply the given function to the DataFrame across the entire object
         """
@@ -460,11 +459,11 @@ def _apply_tablewise(
 
     def _apply_pairwise(
         self,
-        target: FrameOrSeriesUnion,
-        other: FrameOrSeriesUnion | None,
+        target: DataFrame | Series,
+        other: DataFrame | Series | None,
         pairwise: bool | None,
-        func: Callable[[FrameOrSeriesUnion, FrameOrSeriesUnion], FrameOrSeriesUnion],
-    ) -> FrameOrSeriesUnion:
+        func: Callable[[DataFrame | Series, DataFrame | Series], DataFrame | Series],
+    ) -> DataFrame | Series:
         """
         Apply the given pairwise function given 2 pandas objects (DataFrame/Series)
         """
@@ -639,11 +638,11 @@ def _apply(
 
     def _apply_pairwise(
         self,
-        target: FrameOrSeriesUnion,
-        other: FrameOrSeriesUnion | None,
+        target: DataFrame | Series,
+        other: DataFrame | Series | None,
         pairwise: bool | None,
-        func: Callable[[FrameOrSeriesUnion, FrameOrSeriesUnion], FrameOrSeriesUnion],
-    ) -> FrameOrSeriesUnion:
+        func: Callable[[DataFrame | Series, DataFrame | Series], DataFrame | Series],
+    ) -> DataFrame | Series:
         """
         Apply the given pairwise function given 2 pandas objects (DataFrame/Series)
         """
@@ -1379,7 +1378,7 @@ def quantile(self, quantile: float, interpolation: str = "linear", **kwargs):
 
     def cov(
         self,
-        other: FrameOrSeriesUnion | None = None,
+        other: DataFrame | Series | None = None,
         pairwise: bool | None = None,
         ddof: int = 1,
         **kwargs,
@@ -1417,7 +1416,7 @@ def cov_func(x, y):
 
     def corr(
         self,
-        other: FrameOrSeriesUnion | None = None,
+        other: DataFrame | Series | None = None,
         pairwise: bool | None = None,
         ddof: int = 1,
         **kwargs,
@@ -2159,7 +2158,7 @@ def quantile(self, quantile: float, interpolation: str = "linear", **kwargs):
     )
     def cov(
         self,
-        other: FrameOrSeriesUnion | None = None,
+        other: DataFrame | Series | None = None,
         pairwise: bool | None = None,
         ddof: int = 1,
         **kwargs,
@@ -2284,7 +2283,7 @@ def cov(
     )
     def corr(
         self,
-        other: FrameOrSeriesUnion | None = None,
+        other: DataFrame | Series | None = None,
         pairwise: bool | None = None,
         ddof: int = 1,
         **kwargs,
diff --git a/pandas/io/formats/info.py b/pandas/io/formats/info.py
index e014d7d63a35f..64a59778a54f3 100644
--- a/pandas/io/formats/info.py
+++ b/pandas/io/formats/info.py
@@ -16,10 +16,7 @@
 
 from pandas._config import get_option
 
-from pandas._typing import (
-    Dtype,
-    FrameOrSeriesUnion,
-)
+from pandas._typing import Dtype
 
 from pandas.core.indexes.api import Index
 
@@ -27,7 +24,10 @@
 from pandas.io.formats.printing import pprint_thing
 
 if TYPE_CHECKING:
-    from pandas.core.frame import DataFrame
+    from pandas.core.frame import (
+        DataFrame,
+        Series,
+    )
 
 
 def _put_str(s: str | Dtype, space: int) -> str:
@@ -110,7 +110,7 @@ class BaseInfo(ABC):
         values.
     """
 
-    data: FrameOrSeriesUnion
+    data: DataFrame | Series
     memory_usage: bool | str
 
     @property
@@ -413,7 +413,7 @@ def get_lines(self) -> list[str]:
         """Product in a form of list of lines (strings)."""
 
     @property
-    def data(self) -> FrameOrSeriesUnion:
+    def data(self) -> DataFrame | Series:
         return self.info.data
 
     @property
diff --git a/pandas/io/formats/style.py b/pandas/io/formats/style.py
index 93c3843b36846..6732a4517ec3e 100644
--- a/pandas/io/formats/style.py
+++ b/pandas/io/formats/style.py
@@ -23,7 +23,6 @@
     Axis,
     FilePathOrBuffer,
     FrameOrSeries,
-    FrameOrSeriesUnion,
     IndexLabel,
     Scalar,
 )
@@ -171,7 +170,7 @@ class Styler(StylerRenderer):
 
     def __init__(
         self,
-        data: FrameOrSeriesUnion,
+        data: DataFrame | Series,
         precision: int | None = None,
         table_styles: CSSStyles | None = None,
         uuid: str | None = None,
diff --git a/pandas/io/formats/style_render.py b/pandas/io/formats/style_render.py
index 7686d8a340c37..f20c8dcfbca8b 100644
--- a/pandas/io/formats/style_render.py
+++ b/pandas/io/formats/style_render.py
@@ -20,10 +20,7 @@
 from pandas._config import get_option
 
 from pandas._libs import lib
-from pandas._typing import (
-    FrameOrSeriesUnion,
-    TypedDict,
-)
+from pandas._typing import TypedDict
 from pandas.compat._optional import import_optional_dependency
 
 from pandas.core.dtypes.generic import ABCSeries
@@ -70,7 +67,7 @@ class StylerRenderer:
 
     def __init__(
         self,
-        data: FrameOrSeriesUnion,
+        data: DataFrame | Series,
         uuid: str | None = None,
         uuid_len: int = 5,
         table_styles: CSSStyles | None = None,
@@ -1159,7 +1156,7 @@ def _pseudo_css(self, uuid: str, name: str, row: int, col: int, text: str):
             },
         ]
 
-    def _translate(self, styler_data: FrameOrSeriesUnion, uuid: str, d: dict):
+    def _translate(self, styler_data: DataFrame | Series, uuid: str, d: dict):
         """
         Mutate the render dictionary to allow for tooltips:
 
diff --git a/pandas/io/json/_json.py b/pandas/io/json/_json.py
index 77582c46977c1..fdeda868fdb5e 100644
--- a/pandas/io/json/_json.py
+++ b/pandas/io/json/_json.py
@@ -21,7 +21,6 @@
 from pandas._typing import (
     CompressionOptions,
     DtypeArg,
-    FrameOrSeriesUnion,
     IndexLabel,
     JSONSerializable,
     StorageOptions,
@@ -863,7 +862,7 @@ def __init__(
         self.convert_dates = convert_dates
         self.date_unit = date_unit
         self.keep_default_dates = keep_default_dates
-        self.obj: FrameOrSeriesUnion | None = None
+        self.obj: DataFrame | Series | None = None
 
     def check_keys_split(self, decoded):
         """
diff --git a/pandas/io/pytables.py b/pandas/io/pytables.py
index 208b8a008ffe6..3d0a1fe867d21 100644
--- a/pandas/io/pytables.py
+++ b/pandas/io/pytables.py
@@ -40,7 +40,6 @@
     ArrayLike,
     DtypeArg,
     FrameOrSeries,
-    FrameOrSeriesUnion,
     Shape,
 )
 from pandas.compat._optional import import_optional_dependency
@@ -2593,7 +2592,7 @@ class Fixed:
 
     pandas_kind: str
     format_type: str = "fixed"  # GH#30962 needed by dask
-    obj_type: type[FrameOrSeriesUnion]
+    obj_type: type[DataFrame | Series]
     ndim: int
     encoding: str
     parent: HDFStore
@@ -3363,7 +3362,7 @@ def is_multi_index(self) -> bool:
         return isinstance(self.levels, list)
 
     def validate_multiindex(
-        self, obj: FrameOrSeriesUnion
+        self, obj: DataFrame | Series
     ) -> tuple[DataFrame, list[Hashable]]:
         """
         validate that we can store the multi-index; reset and return the
@@ -4500,7 +4499,7 @@ class AppendableFrameTable(AppendableTable):
     pandas_kind = "frame_table"
     table_type = "appendable_frame"
     ndim = 2
-    obj_type: type[FrameOrSeriesUnion] = DataFrame
+    obj_type: type[DataFrame | Series] = DataFrame
 
     @property
     def is_transposed(self) -> bool:
diff --git a/pandas/plotting/_matplotlib/timeseries.py b/pandas/plotting/_matplotlib/timeseries.py
index 3b9c5eae70b42..3cd312b06020d 100644
--- a/pandas/plotting/_matplotlib/timeseries.py
+++ b/pandas/plotting/_matplotlib/timeseries.py
@@ -16,7 +16,6 @@
     to_offset,
 )
 from pandas._libs.tslibs.dtypes import FreqGroup
-from pandas._typing import FrameOrSeriesUnion
 
 from pandas.core.dtypes.generic import (
     ABCDatetimeIndex,
@@ -40,6 +39,7 @@
     from matplotlib.axes import Axes
 
     from pandas import (
+        DataFrame,
         DatetimeIndex,
         Index,
         Series,
@@ -210,7 +210,7 @@ def _get_freq(ax: Axes, series: Series):
     return freq, ax_freq
 
 
-def use_dynamic_x(ax: Axes, data: FrameOrSeriesUnion) -> bool:
+def use_dynamic_x(ax: Axes, data: DataFrame | Series) -> bool:
     freq = _get_index_freq(data.index)
     ax_freq = _get_ax_freq(ax)
 
diff --git a/pandas/plotting/_matplotlib/tools.py b/pandas/plotting/_matplotlib/tools.py
index 9bfa24b6371ab..9d509d02c2e4f 100644
--- a/pandas/plotting/_matplotlib/tools.py
+++ b/pandas/plotting/_matplotlib/tools.py
@@ -13,8 +13,6 @@
 import matplotlib.ticker as ticker
 import numpy as np
 
-from pandas._typing import FrameOrSeriesUnion
-
 from pandas.core.dtypes.common import is_list_like
 from pandas.core.dtypes.generic import (
     ABCDataFrame,
@@ -31,6 +29,11 @@
     from matplotlib.lines import Line2D
     from matplotlib.table import Table
 
+    from pandas import (
+        DataFrame,
+        Series,
+    )
+
 
 def do_adjust_figure(fig: Figure):
     """Whether fig has constrained_layout enabled."""
@@ -55,7 +58,7 @@ def format_date_labels(ax: Axes, rot):
 
 
 def table(
-    ax, data: FrameOrSeriesUnion, rowLabels=None, colLabels=None, **kwargs
+    ax, data: DataFrame | Series, rowLabels=None, colLabels=None, **kwargs
 ) -> Table:
     if isinstance(data, ABCSeries):
         data = data.to_frame()