diff --git a/pandas/core/indexes/datetimelike.py b/pandas/core/indexes/datetimelike.py
index e3eeca2c45e76..66723969c9f10 100644
--- a/pandas/core/indexes/datetimelike.py
+++ b/pandas/core/indexes/datetimelike.py
@@ -80,7 +80,16 @@ def wrapper(left, right):
     cache=True,
 )
 @inherit_names(
-    ["__iter__", "mean", "freq", "freqstr", "_ndarray_values", "asi8", "_box_values"],
+    [
+        "__iter__",
+        "mean",
+        "freq",
+        "freqstr",
+        "_ndarray_values",
+        "asi8",
+        "_box_values",
+        "_box_func",
+    ],
     DatetimeLikeArrayMixin,
 )
 class DatetimeIndexOpsMixin(ExtensionIndex):
diff --git a/pandas/core/indexes/datetimes.py b/pandas/core/indexes/datetimes.py
index 2b4636155111f..e3245d6e419ed 100644
--- a/pandas/core/indexes/datetimes.py
+++ b/pandas/core/indexes/datetimes.py
@@ -70,7 +70,6 @@ def _new_DatetimeIndex(cls, d):
         "_field_ops",
         "_datetimelike_ops",
         "_datetimelike_methods",
-        "_box_func",
         "tz",
         "tzinfo",
         "dtype",
diff --git a/pandas/core/indexes/period.py b/pandas/core/indexes/period.py
index 75c100c9d2c08..ad88608dba1c9 100644
--- a/pandas/core/indexes/period.py
+++ b/pandas/core/indexes/period.py
@@ -280,22 +280,6 @@ def _shallow_copy_with_infer(self, values=None, **kwargs):
         """ we always want to return a PeriodIndex """
         return self._shallow_copy(values=values, **kwargs)
 
-    @property
-    def _box_func(self):
-        """Maybe box an ordinal or Period"""
-        # TODO(DatetimeArray): Avoid double-boxing
-        # PeriodArray takes care of boxing already, so we need to check
-        # whether we're given an ordinal or a Period. It seems like some
-        # places outside of indexes/period.py are calling this _box_func,
-        # but passing data that's already boxed.
-        def func(x):
-            if isinstance(x, Period) or x is NaT:
-                return x
-            else:
-                return Period._from_ordinal(ordinal=x, freq=self.freq)
-
-        return func
-
     def _maybe_convert_timedelta(self, other):
         """
         Convert timedelta-like input to an integer multiple of self.freq
diff --git a/pandas/core/indexes/timedeltas.py b/pandas/core/indexes/timedeltas.py
index 08a07e8d30348..f5cf87ea700a6 100644
--- a/pandas/core/indexes/timedeltas.py
+++ b/pandas/core/indexes/timedeltas.py
@@ -53,7 +53,6 @@
         "_datetimelike_methods",
         "_other_ops",
         "components",
-        "_box_func",
         "to_pytimedelta",
         "sum",
         "std",