diff --git a/pandas/core/indexes/datetimes.py b/pandas/core/indexes/datetimes.py
index f71fd0d406c54..e66f513e347a9 100644
--- a/pandas/core/indexes/datetimes.py
+++ b/pandas/core/indexes/datetimes.py
@@ -75,7 +75,7 @@ def _new_DatetimeIndex(cls, d):
     + [
         method
         for method in DatetimeArray._datetimelike_methods
-        if method not in ("tz_localize",)
+        if method not in ("tz_localize", "tz_convert")
     ],
     DatetimeArray,
     wrap=True,
@@ -228,6 +228,11 @@ class DatetimeIndex(DatetimeTimedeltaMixin):
     # --------------------------------------------------------------------
     # methods that dispatch to array and wrap result in DatetimeIndex
 
+    @doc(DatetimeArray.tz_convert)
+    def tz_convert(self, tz) -> "DatetimeIndex":
+        arr = self._data.tz_convert(tz)
+        return type(self)._simple_new(arr, name=self.name)
+
     @doc(DatetimeArray.tz_localize)
     def tz_localize(
         self, tz, ambiguous="raise", nonexistent="raise"
diff --git a/pandas/core/tools/datetimes.py b/pandas/core/tools/datetimes.py
index 3c1fe6bacefcf..8fcc5f74ea897 100644
--- a/pandas/core/tools/datetimes.py
+++ b/pandas/core/tools/datetimes.py
@@ -307,9 +307,7 @@ def _convert_listlike_datetimes(
         if not isinstance(arg, (DatetimeArray, DatetimeIndex)):
             return DatetimeIndex(arg, tz=tz, name=name)
         if tz == "utc":
-            # error: Item "DatetimeIndex" of "Union[DatetimeArray, DatetimeIndex]" has
-            # no attribute "tz_convert"
-            arg = arg.tz_convert(None).tz_localize(tz)  # type: ignore[union-attr]
+            arg = arg.tz_convert(None).tz_localize(tz)
         return arg
 
     elif is_datetime64_ns_dtype(arg_dtype):
diff --git a/setup.cfg b/setup.cfg
index aa1535a171f0a..2ba22e5aad3c7 100644
--- a/setup.cfg
+++ b/setup.cfg
@@ -157,9 +157,6 @@ check_untyped_defs=False
 [mypy-pandas.core.computation.scope]
 check_untyped_defs=False
 
-[mypy-pandas.core.dtypes.cast]
-check_untyped_defs=False
-
 [mypy-pandas.core.frame]
 check_untyped_defs=False