diff --git a/pandas/core/series.py b/pandas/core/series.py
index 11a59f261de5c..12a202edab1d3 100644
--- a/pandas/core/series.py
+++ b/pandas/core/series.py
@@ -6034,7 +6034,7 @@ def _flex_method(self, other, op, *, level=None, fill_value=None, axis: Axis = 0
 
         if isinstance(other, Series):
             return self._binop(other, op, level=level, fill_value=fill_value)
-        elif isinstance(other, (np.ndarray, list, tuple)):
+        elif isinstance(other, (np.ndarray, list, tuple, ExtensionArray)):
             if len(other) != len(self):
                 raise ValueError("Lengths must be equal")
             other = self._constructor(other, self.index, copy=False)
diff --git a/pandas/tests/series/test_arithmetic.py b/pandas/tests/series/test_arithmetic.py
index 35a9742d653db..16caa55e36c0b 100644
--- a/pandas/tests/series/test_arithmetic.py
+++ b/pandas/tests/series/test_arithmetic.py
@@ -155,6 +155,27 @@ def _check_fill(meth, op, a, b, fill_value=0):
         # should accept axis=0 or axis='rows'
         op(a, b, axis=0)
 
+    @pytest.mark.parametrize("kind", ["datetime", "timedelta"])
+    def test_rhs_extension_array_sub_with_fill_value(self, kind):
+        if kind == "datetime":
+            left = Series(
+                [pd.Timestamp("2025-08-20"), pd.Timestamp("2025-08-21")],
+                dtype=np.dtype("datetime64[ns]"),
+            )
+        else:
+            left = Series(
+                [Timedelta(days=1), Timedelta(days=2)],
+                dtype=np.dtype("timedelta64[ns]"),
+            )
+
+        right = (
+            left._values
+        )  # DatetimeArray or TimedeltaArray which is an ExtensionArray
+
+        result = left.sub(right, fill_value=left.iloc[0])
+        expected = Series(np.zeros(len(left), dtype=np.dtype("timedelta64[ns]")))
+        tm.assert_series_equal(result, expected)
+
 
 class TestSeriesArithmetic:
     # Some of these may end up in tests/arithmetic, but are not yet sorted
@@ -404,6 +425,21 @@ def test_comparison_flex_alignment(self, values, op):
         expected = Series(values, index=list("abcd"))
         tm.assert_series_equal(result, expected)
 
+    @pytest.mark.parametrize(
+        "left",
+        [
+            Series(Categorical(["a", "b", "a"])),
+            Series(pd.period_range("2020Q1", periods=3, freq="Q")),
+        ],
+        ids=["categorical", "period"],
+    )
+    def test_rhs_extension_array_eq_with_fill_value(self, left):
+        right = left._values  # this is an ExtensionArray
+
+        result = left.eq(right, fill_value=left.iloc[0])
+        expected = Series([True, True, True])
+        tm.assert_series_equal(result, expected)
+
     @pytest.mark.parametrize(
         "values, op, fill_value",
         [