diff --git a/doc/source/whatsnew/v2.0.0.rst b/doc/source/whatsnew/v2.0.0.rst
index 6239ddf9442e7..3f26d09a54a76 100644
--- a/doc/source/whatsnew/v2.0.0.rst
+++ b/doc/source/whatsnew/v2.0.0.rst
@@ -180,6 +180,7 @@ Removal of prior version deprecations/changes
 - Removed argument ``how`` from :meth:`PeriodIndex.astype`, use :meth:`PeriodIndex.to_timestamp` instead (:issue:`37982`)
 - Removed argument ``try_cast`` from :meth:`DataFrame.mask`, :meth:`DataFrame.where`, :meth:`Series.mask` and :meth:`Series.where` (:issue:`38836`)
 - Removed argument ``is_copy`` from :meth:`DataFrame.take` and :meth:`Series.take` (:issue:`30615`)
+- Removed argument ``kind`` from :meth:`Index.get_slice_bound`, :meth:`Index.slice_indexer` and :meth:`Index.slice_locs` (:issue:`41378`)
 - Disallow passing non-round floats to :class:`Timestamp` with ``unit="M"`` or ``unit="Y"`` (:issue:`47266`)
 - Remove keywords ``convert_float`` and ``mangle_dupe_cols`` from :func:`read_excel` (:issue:`41176`)
 - Disallow passing non-keyword arguments to :func:`read_excel` except ``io`` and ``sheet_name`` (:issue:`34418`)
diff --git a/pandas/core/indexes/base.py b/pandas/core/indexes/base.py
index 7d680688f4731..4e513dcc8b551 100644
--- a/pandas/core/indexes/base.py
+++ b/pandas/core/indexes/base.py
@@ -6471,7 +6471,6 @@ def slice_indexer(
         start: Hashable | None = None,
         end: Hashable | None = None,
         step: int | None = None,
-        kind=no_default,
     ) -> slice:
         """
         Compute the slice indexer for input labels and step.
@@ -6485,9 +6484,6 @@ def slice_indexer(
         end : label, default None
             If None, defaults to the end.
         step : int, default None
-        kind : str, default None
-
-            .. deprecated:: 1.4.0
 
         Returns
         -------
@@ -6514,8 +6510,6 @@ def slice_indexer(
         >>> idx.slice_indexer(start='b', end=('c', 'g'))
         slice(1, 3, None)
         """
-        self._deprecated_arg(kind, "kind", "slice_indexer")
-
         start_slice, end_slice = self.slice_locs(start, end, step=step)
 
         # return a slice
@@ -6550,7 +6544,7 @@ def _validate_indexer(self, form: str_t, key, kind: str_t) -> None:
         if key is not None and not is_integer(key):
             self._raise_invalid_indexer(form, key)
 
-    def _maybe_cast_slice_bound(self, label, side: str_t, kind=no_default):
+    def _maybe_cast_slice_bound(self, label, side: str_t):
         """
         This function should be overloaded in subclasses that allow non-trivial
         casting on label-slice bounds, e.g. datetime-like indices allowing
@@ -6560,9 +6554,6 @@ def _maybe_cast_slice_bound(self, label, side: str_t, kind=no_default):
         ----------
         label : object
         side : {'left', 'right'}
-        kind : {'loc', 'getitem'} or None
-
-            .. deprecated:: 1.3.0
 
         Returns
         -------
@@ -6572,8 +6563,6 @@ def _maybe_cast_slice_bound(self, label, side: str_t, kind=no_default):
         -----
         Value of `side` parameter should be validated in caller.
         """
-        assert kind in ["loc", "getitem", None, no_default]
-        self._deprecated_arg(kind, "kind", "_maybe_cast_slice_bound")
 
         # We are a plain index here (sub-class override this method if they
         # wish to have special treatment for floats/ints, e.g. Float64Index and
@@ -6598,9 +6587,7 @@ def _searchsorted_monotonic(self, label, side: Literal["left", "right"] = "left"
 
         raise ValueError("index must be monotonic increasing or decreasing")
 
-    def get_slice_bound(
-        self, label, side: Literal["left", "right"], kind=no_default
-    ) -> int:
+    def get_slice_bound(self, label, side: Literal["left", "right"]) -> int:
         """
         Calculate slice bound that corresponds to given label.
 
@@ -6611,17 +6598,12 @@ def get_slice_bound(
         ----------
         label : object
         side : {'left', 'right'}
-        kind : {'loc', 'getitem'} or None
-
-            .. deprecated:: 1.4.0
 
         Returns
         -------
         int
             Index of label.
         """
-        assert kind in ["loc", "getitem", None, no_default]
-        self._deprecated_arg(kind, "kind", "get_slice_bound")
 
         if side not in ("left", "right"):
             raise ValueError(
@@ -6667,9 +6649,7 @@ def get_slice_bound(
             else:
                 return slc
 
-    def slice_locs(
-        self, start=None, end=None, step=None, kind=no_default
-    ) -> tuple[int, int]:
+    def slice_locs(self, start=None, end=None, step=None) -> tuple[int, int]:
         """
         Compute slice locations for input labels.
 
@@ -6681,9 +6661,6 @@ def slice_locs(
             If None, defaults to the end.
         step : int, defaults None
             If None, defaults to 1.
-        kind : {'loc', 'getitem'} or None
-
-            .. deprecated:: 1.4.0
 
         Returns
         -------
@@ -6703,7 +6680,6 @@ def slice_locs(
         >>> idx.slice_locs(start='b', end='c')
         (1, 3)
         """
-        self._deprecated_arg(kind, "kind", "slice_locs")
         inc = step is None or step >= 0
 
         if not inc:
diff --git a/pandas/core/indexes/datetimelike.py b/pandas/core/indexes/datetimelike.py
index 3cf3e50a24c3f..c6c8695ab01da 100644
--- a/pandas/core/indexes/datetimelike.py
+++ b/pandas/core/indexes/datetimelike.py
@@ -290,7 +290,7 @@ def _partial_date_slice(
             # try to find the dates
             return (lhs_mask & rhs_mask).nonzero()[0]
 
-    def _maybe_cast_slice_bound(self, label, side: str, kind=lib.no_default):
+    def _maybe_cast_slice_bound(self, label, side: str):
         """
         If label is a string, cast it to scalar type according to resolution.
 
@@ -298,7 +298,6 @@ def _maybe_cast_slice_bound(self, label, side: str, kind=lib.no_default):
         ----------
         label : object
         side : {'left', 'right'}
-        kind : {'loc', 'getitem'} or None
 
         Returns
         -------
@@ -308,9 +307,6 @@ def _maybe_cast_slice_bound(self, label, side: str, kind=lib.no_default):
         -----
         Value of `side` parameter should be validated in caller.
         """
-        assert kind in ["loc", "getitem", None, lib.no_default]
-        self._deprecated_arg(kind, "kind", "_maybe_cast_slice_bound")
-
         if isinstance(label, str):
             try:
                 parsed, reso = self._parse_with_reso(label)
diff --git a/pandas/core/indexes/datetimes.py b/pandas/core/indexes/datetimes.py
index b08a0d3a60526..32a4b87e9cb33 100644
--- a/pandas/core/indexes/datetimes.py
+++ b/pandas/core/indexes/datetimes.py
@@ -714,7 +714,7 @@ def _maybe_cast_for_get_loc(self, key) -> Timestamp:
         return key
 
     @doc(DatetimeTimedeltaMixin._maybe_cast_slice_bound)
-    def _maybe_cast_slice_bound(self, label, side: str, kind=lib.no_default):
+    def _maybe_cast_slice_bound(self, label, side: str):
 
         # GH#42855 handle date here instead of get_slice_bound
         if isinstance(label, date) and not isinstance(label, datetime):
@@ -722,11 +722,11 @@ def _maybe_cast_slice_bound(self, label, side: str, kind=lib.no_default):
             # https://github.com/pandas-dev/pandas/issues/31501
             label = Timestamp(label).to_pydatetime()
 
-        label = super()._maybe_cast_slice_bound(label, side, kind=kind)
+        label = super()._maybe_cast_slice_bound(label, side)
         self._deprecate_mismatched_indexing(label)
         return self._maybe_cast_for_get_loc(label)
 
-    def slice_indexer(self, start=None, end=None, step=None, kind=lib.no_default):
+    def slice_indexer(self, start=None, end=None, step=None):
         """
         Return indexer for specified label slice.
         Index.slice_indexer, customized to handle time slicing.
@@ -740,8 +740,6 @@ def slice_indexer(self, start=None, end=None, step=None, kind=lib.no_default):
           value-based selection in non-monotonic cases.
 
         """
-        self._deprecated_arg(kind, "kind", "slice_indexer")
-
         # For historical reasons DatetimeIndex supports slices between two
         # instances of datetime.time as if it were applying a slice mask to
         # an array of (self.hour, self.minute, self.seconds, self.microsecond).
@@ -764,7 +762,7 @@ def check_str_or_none(point) -> bool:
             or check_str_or_none(end)
             or self.is_monotonic_increasing
         ):
-            return Index.slice_indexer(self, start, end, step, kind=kind)
+            return Index.slice_indexer(self, start, end, step)
 
         mask = np.array(True)
         deprecation_mask = np.array(True)
diff --git a/pandas/core/indexes/interval.py b/pandas/core/indexes/interval.py
index 3eb3226328a61..8507280a6cc8d 100644
--- a/pandas/core/indexes/interval.py
+++ b/pandas/core/indexes/interval.py
@@ -786,8 +786,7 @@ def _should_fallback_to_positional(self) -> bool:
         # ExtensionDtype]" has no attribute "subtype"
         return self.dtype.subtype.kind in ["m", "M"]  # type: ignore[union-attr]
 
-    def _maybe_cast_slice_bound(self, label, side: str, kind=lib.no_default):
-        self._deprecated_arg(kind, "kind", "_maybe_cast_slice_bound")
+    def _maybe_cast_slice_bound(self, label, side: str):
         return getattr(self, side)._maybe_cast_slice_bound(label, side)
 
     def _is_comparable_dtype(self, dtype: DtypeObj) -> bool:
diff --git a/pandas/core/indexes/multi.py b/pandas/core/indexes/multi.py
index 59a0179f93c10..4f8586a4bba13 100644
--- a/pandas/core/indexes/multi.py
+++ b/pandas/core/indexes/multi.py
@@ -2627,7 +2627,6 @@ def get_slice_bound(
         self,
         label: Hashable | Sequence[Hashable],
         side: Literal["left", "right"],
-        kind=lib.no_default,
     ) -> int:
         """
         For an ordered MultiIndex, compute slice bound
@@ -2640,9 +2639,6 @@ def get_slice_bound(
         ----------
         label : object or tuple of objects
         side : {'left', 'right'}
-        kind : {'loc', 'getitem', None}
-
-            .. deprecated:: 1.4.0
 
         Returns
         -------
@@ -2675,15 +2671,11 @@ def get_slice_bound(
         MultiIndex.get_locs : Get location for a label/slice/list/mask or a
                               sequence of such.
         """
-        self._deprecated_arg(kind, "kind", "get_slice_bound")
-
         if not isinstance(label, tuple):
             label = (label,)
         return self._partial_tup_index(label, side=side)
 
-    def slice_locs(
-        self, start=None, end=None, step=None, kind=lib.no_default
-    ) -> tuple[int, int]:
+    def slice_locs(self, start=None, end=None, step=None) -> tuple[int, int]:
         """
         For an ordered MultiIndex, compute the slice locations for input
         labels.
@@ -2700,9 +2692,6 @@ def slice_locs(
             If None, defaults to the end
         step : int or None
             Slice step
-        kind : string, optional, defaults None
-
-            .. deprecated:: 1.4.0
 
         Returns
         -------
@@ -2737,7 +2726,6 @@ def slice_locs(
         MultiIndex.get_locs : Get location for a label/slice/list/mask or a
                               sequence of such.
         """
-        self._deprecated_arg(kind, "kind", "slice_locs")
         # This function adds nothing to its parent implementation (the magic
         # happens in get_slice_bound method), but it adds meaningful doc.
         return super().slice_locs(start, end, step)
diff --git a/pandas/core/indexes/numeric.py b/pandas/core/indexes/numeric.py
index f0f6dfe4eb147..2cb814be6472c 100644
--- a/pandas/core/indexes/numeric.py
+++ b/pandas/core/indexes/numeric.py
@@ -233,10 +233,7 @@ def _convert_slice_indexer(self, key: slice, kind: str, is_frame: bool = False):
         return super()._convert_slice_indexer(key, kind=kind, is_frame=is_frame)
 
     @doc(Index._maybe_cast_slice_bound)
-    def _maybe_cast_slice_bound(self, label, side: str, kind=lib.no_default):
-        assert kind in ["loc", "getitem", None, lib.no_default]
-        self._deprecated_arg(kind, "kind", "_maybe_cast_slice_bound")
-
+    def _maybe_cast_slice_bound(self, label, side: str):
         # we will try to coerce to integers
         return self._maybe_cast_indexer(label)
 
diff --git a/pandas/core/indexes/period.py b/pandas/core/indexes/period.py
index d67bcfdc78261..a09b987496a40 100644
--- a/pandas/core/indexes/period.py
+++ b/pandas/core/indexes/period.py
@@ -8,10 +8,7 @@
 
 import numpy as np
 
-from pandas._libs import (
-    index as libindex,
-    lib,
-)
+from pandas._libs import index as libindex
 from pandas._libs.tslibs import (
     BaseOffset,
     NaT,
@@ -474,11 +471,11 @@ def _cast_partial_indexing_scalar(self, label):
         return key
 
     @doc(DatetimeIndexOpsMixin._maybe_cast_slice_bound)
-    def _maybe_cast_slice_bound(self, label, side: str, kind=lib.no_default):
+    def _maybe_cast_slice_bound(self, label, side: str):
         if isinstance(label, datetime):
             label = self._cast_partial_indexing_scalar(label)
 
-        return super()._maybe_cast_slice_bound(label, side, kind=kind)
+        return super()._maybe_cast_slice_bound(label, side)
 
     def _parsed_string_to_bounds(self, reso: Resolution, parsed: datetime):
         iv = Period(parsed, freq=reso.attr_abbrev)
diff --git a/pandas/tests/indexes/base_class/test_indexing.py b/pandas/tests/indexes/base_class/test_indexing.py
index 770fa3f6e5dc1..070fec47b90e6 100644
--- a/pandas/tests/indexes/base_class/test_indexing.py
+++ b/pandas/tests/indexes/base_class/test_indexing.py
@@ -10,23 +10,19 @@
 
 
 class TestGetSliceBounds:
-    @pytest.mark.parametrize("kind", ["getitem", "loc", None])
     @pytest.mark.parametrize("side, expected", [("left", 4), ("right", 5)])
-    def test_get_slice_bounds_within(self, kind, side, expected):
+    def test_get_slice_bounds_within(self, side, expected):
         index = Index(list("abcdef"))
-        with tm.assert_produces_warning(FutureWarning, match="'kind' argument"):
-            result = index.get_slice_bound("e", kind=kind, side=side)
+        result = index.get_slice_bound("e", side=side)
         assert result == expected
 
-    @pytest.mark.parametrize("kind", ["getitem", "loc", None])
     @pytest.mark.parametrize("side", ["left", "right"])
     @pytest.mark.parametrize(
         "data, bound, expected", [(list("abcdef"), "x", 6), (list("bcdefg"), "a", 0)]
     )
-    def test_get_slice_bounds_outside(self, kind, side, expected, data, bound):
+    def test_get_slice_bounds_outside(self, side, expected, data, bound):
         index = Index(data)
-        with tm.assert_produces_warning(FutureWarning, match="'kind' argument"):
-            result = index.get_slice_bound(bound, kind=kind, side=side)
+        result = index.get_slice_bound(bound, side=side)
         assert result == expected
 
     def test_get_slice_bounds_invalid_side(self):
diff --git a/pandas/tests/indexes/datetimes/test_indexing.py b/pandas/tests/indexes/datetimes/test_indexing.py
index 5c8724a2a1c22..87bf0199b2528 100644
--- a/pandas/tests/indexes/datetimes/test_indexing.py
+++ b/pandas/tests/indexes/datetimes/test_indexing.py
@@ -712,10 +712,9 @@ def test_maybe_cast_slice_duplicate_monotonic(self):
 
 class TestGetSliceBounds:
     @pytest.mark.parametrize("box", [date, datetime, Timestamp])
-    @pytest.mark.parametrize("kind", ["getitem", "loc", None])
     @pytest.mark.parametrize("side, expected", [("left", 4), ("right", 5)])
     def test_get_slice_bounds_datetime_within(
-        self, box, kind, side, expected, tz_aware_fixture
+        self, box, side, expected, tz_aware_fixture
     ):
         # GH 35690
         tz = tz_aware_fixture
@@ -725,15 +724,14 @@ def test_get_slice_bounds_datetime_within(
         warn = None if tz is None else FutureWarning
         with tm.assert_produces_warning(warn):
             # GH#36148 will require tzawareness-compat
-            result = index.get_slice_bound(key, kind=kind, side=side)
+            result = index.get_slice_bound(key, side=side)
         assert result == expected
 
     @pytest.mark.parametrize("box", [datetime, Timestamp])
-    @pytest.mark.parametrize("kind", ["getitem", "loc", None])
     @pytest.mark.parametrize("side", ["left", "right"])
     @pytest.mark.parametrize("year, expected", [(1999, 0), (2020, 30)])
     def test_get_slice_bounds_datetime_outside(
-        self, box, kind, side, year, expected, tz_aware_fixture
+        self, box, side, year, expected, tz_aware_fixture
     ):
         # GH 35690
         tz = tz_aware_fixture
@@ -743,12 +741,11 @@ def test_get_slice_bounds_datetime_outside(
         warn = None if tz is None else FutureWarning
         with tm.assert_produces_warning(warn):
             # GH#36148 will require tzawareness-compat
-            result = index.get_slice_bound(key, kind=kind, side=side)
+            result = index.get_slice_bound(key, side=side)
         assert result == expected
 
     @pytest.mark.parametrize("box", [datetime, Timestamp])
-    @pytest.mark.parametrize("kind", ["getitem", "loc", None])
-    def test_slice_datetime_locs(self, box, kind, tz_aware_fixture):
+    def test_slice_datetime_locs(self, box, tz_aware_fixture):
         # GH 34077
         tz = tz_aware_fixture
         index = DatetimeIndex(["2010-01-01", "2010-01-03"]).tz_localize(tz)
diff --git a/pandas/tests/indexes/multi/test_indexing.py b/pandas/tests/indexes/multi/test_indexing.py
index 7519a3e10811d..fce3da6dd6aee 100644
--- a/pandas/tests/indexes/multi/test_indexing.py
+++ b/pandas/tests/indexes/multi/test_indexing.py
@@ -841,8 +841,7 @@ def test_timestamp_multiindex_indexer():
 def test_get_slice_bound_with_missing_value(index_arr, expected, target, algo):
     # issue 19132
     idx = MultiIndex.from_arrays(index_arr)
-    with tm.assert_produces_warning(FutureWarning, match="'kind' argument"):
-        result = idx.get_slice_bound(target, side=algo, kind="loc")
+    result = idx.get_slice_bound(target, side=algo)
     assert result == expected
 
 
diff --git a/pandas/tests/indexes/numeric/test_indexing.py b/pandas/tests/indexes/numeric/test_indexing.py
index 1c4cbd21a988e..0c2c5e0b903bc 100644
--- a/pandas/tests/indexes/numeric/test_indexing.py
+++ b/pandas/tests/indexes/numeric/test_indexing.py
@@ -576,20 +576,15 @@ def test_slice_locs_na_raises(self):
 
 
 class TestGetSliceBounds:
-    @pytest.mark.parametrize("kind", ["getitem", "loc", None])
     @pytest.mark.parametrize("side, expected", [("left", 4), ("right", 5)])
-    def test_get_slice_bounds_within(self, kind, side, expected):
+    def test_get_slice_bounds_within(self, side, expected):
         index = Index(range(6))
-        with tm.assert_produces_warning(FutureWarning, match="'kind' argument"):
-
-            result = index.get_slice_bound(4, kind=kind, side=side)
+        result = index.get_slice_bound(4, side=side)
         assert result == expected
 
-    @pytest.mark.parametrize("kind", ["getitem", "loc", None])
     @pytest.mark.parametrize("side", ["left", "right"])
     @pytest.mark.parametrize("bound, expected", [(-1, 0), (10, 6)])
-    def test_get_slice_bounds_outside(self, kind, side, expected, bound):
+    def test_get_slice_bounds_outside(self, side, expected, bound):
         index = Index(range(6))
-        with tm.assert_produces_warning(FutureWarning, match="'kind' argument"):
-            result = index.get_slice_bound(bound, kind=kind, side=side)
+        result = index.get_slice_bound(bound, side=side)
         assert result == expected
diff --git a/pandas/tests/indexes/test_indexing.py b/pandas/tests/indexes/test_indexing.py
index a0cb6691cb6a0..2b7c5745e0c67 100644
--- a/pandas/tests/indexes/test_indexing.py
+++ b/pandas/tests/indexes/test_indexing.py
@@ -297,19 +297,6 @@ def test_getitem_deprecated_float(idx):
     assert result == expected
 
 
-def test_maybe_cast_slice_bound_kind_deprecated(index):
-    if not len(index):
-        return
-
-    with tm.assert_produces_warning(FutureWarning):
-        # passed as keyword
-        index._maybe_cast_slice_bound(index[0], "left", kind="loc")
-
-    with tm.assert_produces_warning(FutureWarning):
-        # pass as positional
-        index._maybe_cast_slice_bound(index[0], "left", "loc")
-
-
 @pytest.mark.parametrize(
     "idx,target,expected",
     [