diff --git a/pandas/_libs/tslibs/offsets.pyx b/pandas/_libs/tslibs/offsets.pyx
index 68a0a4a403c81..327d1067dd17d 100644
--- a/pandas/_libs/tslibs/offsets.pyx
+++ b/pandas/_libs/tslibs/offsets.pyx
@@ -328,7 +328,7 @@ class _BaseOffset:
     def __setattr__(self, name, value):
         raise AttributeError("DateOffset objects are immutable.")
 
-    def __eq__(self, other):
+    def __eq__(self, other) -> bool:
         if isinstance(other, str):
             try:
                 # GH#23524 if to_offset fails, we are dealing with an
diff --git a/pandas/core/arrays/sparse/dtype.py b/pandas/core/arrays/sparse/dtype.py
index 4de958cc386b9..3b656705f5568 100644
--- a/pandas/core/arrays/sparse/dtype.py
+++ b/pandas/core/arrays/sparse/dtype.py
@@ -90,7 +90,7 @@ def __hash__(self):
         # __eq__, so we explicitly do it here.
         return super().__hash__()
 
-    def __eq__(self, other):
+    def __eq__(self, other) -> bool:
         # We have to override __eq__ to handle NA values in _metadata.
         # The base class does simple == checks, which fail for NA.
         if isinstance(other, str):
diff --git a/pandas/core/dtypes/dtypes.py b/pandas/core/dtypes/dtypes.py
index 523c8e8bd02d0..2c601b01dbae5 100644
--- a/pandas/core/dtypes/dtypes.py
+++ b/pandas/core/dtypes/dtypes.py
@@ -765,7 +765,7 @@ def __hash__(self) -> int:
         # TODO: update this.
         return hash(str(self))
 
-    def __eq__(self, other):
+    def __eq__(self, other) -> bool:
         if isinstance(other, str):
             return other == self.name
 
@@ -904,7 +904,7 @@ def __hash__(self) -> int:
         # make myself hashable
         return hash(str(self))
 
-    def __eq__(self, other):
+    def __eq__(self, other) -> bool:
         if isinstance(other, str):
             return other == self.name or other == self.name.title()
 
@@ -1077,7 +1077,7 @@ def __hash__(self) -> int:
         # make myself hashable
         return hash(str(self))
 
-    def __eq__(self, other):
+    def __eq__(self, other) -> bool:
         if isinstance(other, str):
             return other.lower() in (self.name.lower(), str(self).lower())
         elif not isinstance(other, IntervalDtype):
diff --git a/pandas/core/indexes/frozen.py b/pandas/core/indexes/frozen.py
index 2c9521d23f71a..13c386187a9e5 100644
--- a/pandas/core/indexes/frozen.py
+++ b/pandas/core/indexes/frozen.py
@@ -77,7 +77,7 @@ def __radd__(self, other):
             other = list(other)
         return self.__class__(other + list(self))
 
-    def __eq__(self, other):
+    def __eq__(self, other) -> bool:
         if isinstance(other, (tuple, FrozenList)):
             other = list(other)
         return super().__eq__(other)
diff --git a/pandas/io/pytables.py b/pandas/io/pytables.py
index 18ae081caf69d..35205aa7dc267 100644
--- a/pandas/io/pytables.py
+++ b/pandas/io/pytables.py
@@ -2092,7 +2092,7 @@ def __repr__(self) -> str:
             )
         )
 
-    def __eq__(self, other):
+    def __eq__(self, other) -> bool:
         """ compare 2 col items """
         return all(
             getattr(self, a, None) == getattr(other, a, None)
diff --git a/pandas/io/stata.py b/pandas/io/stata.py
index 567eeb7f5cdc8..bd5e215730397 100644
--- a/pandas/io/stata.py
+++ b/pandas/io/stata.py
@@ -859,7 +859,7 @@ def __repr__(self) -> str:
         # not perfect :-/
         return "{cls}({obj})".format(cls=self.__class__, obj=self)
 
-    def __eq__(self, other):
+    def __eq__(self, other) -> bool:
         return (
             isinstance(other, self.__class__)
             and self.string == other.string
diff --git a/pandas/tests/indexing/test_indexing.py b/pandas/tests/indexing/test_indexing.py
index ea9bc91a13111..09a66efb6a312 100644
--- a/pandas/tests/indexing/test_indexing.py
+++ b/pandas/tests/indexing/test_indexing.py
@@ -595,7 +595,7 @@ def __str__(self) -> str:
 
             __repr__ = __str__
 
-            def __eq__(self, other):
+            def __eq__(self, other) -> bool:
                 return self.value == other.value
 
             def view(self):
diff --git a/pandas/tests/scalar/timestamp/test_comparisons.py b/pandas/tests/scalar/timestamp/test_comparisons.py
index 4ff0f84327854..fce4fa6eb1eaa 100644
--- a/pandas/tests/scalar/timestamp/test_comparisons.py
+++ b/pandas/tests/scalar/timestamp/test_comparisons.py
@@ -179,8 +179,8 @@ def __gt__(self, o):
         def __ge__(self, o):
             return True
 
-        def __eq__(self, o):
-            return isinstance(o, Inf)
+        def __eq__(self, other) -> bool:
+            return isinstance(other, Inf)
 
     inf = Inf()
     timestamp = Timestamp("2018-11-30")
diff --git a/pandas/tests/series/test_ufunc.py b/pandas/tests/series/test_ufunc.py
index c8a127f89bf91..977e7ded1f1a7 100644
--- a/pandas/tests/series/test_ufunc.py
+++ b/pandas/tests/series/test_ufunc.py
@@ -282,7 +282,7 @@ def __add__(self, other):
             other = getattr(other, "value", other)
             return type(self)(self.value + other)
 
-        def __eq__(self, other):
+        def __eq__(self, other) -> bool:
             return type(other) is Thing and self.value == other.value
 
         def __repr__(self) -> str:
diff --git a/pandas/tests/test_algos.py b/pandas/tests/test_algos.py
index 9e89a1b6f0467..02b50d84c6eca 100644
--- a/pandas/tests/test_algos.py
+++ b/pandas/tests/test_algos.py
@@ -767,7 +767,7 @@ def test_same_object_is_in(self):
         # with similar behavior, then we at least should
         # fall back to usual python's behavior: "a in [a] == True"
         class LikeNan:
-            def __eq__(self, other):
+            def __eq__(self, other) -> bool:
                 return False
 
             def __hash__(self):
diff --git a/pandas/tseries/offsets.py b/pandas/tseries/offsets.py
index e516d30d5490f..0620f2b9aae49 100644
--- a/pandas/tseries/offsets.py
+++ b/pandas/tseries/offsets.py
@@ -2577,7 +2577,7 @@ def __add__(self, other):
                 "will overflow".format(self=self, other=other)
             )
 
-    def __eq__(self, other):
+    def __eq__(self, other) -> bool:
         if isinstance(other, str):
             from pandas.tseries.frequencies import to_offset