diff --git a/airflow/models/baseoperator.py b/airflow/models/baseoperator.py
index 9e0c8e1e69b61..e792fe3cacaab 100644
--- a/airflow/models/baseoperator.py
+++ b/airflow/models/baseoperator.py
@@ -44,7 +44,6 @@
     NoReturn,
     Sequence,
     TypeVar,
-    Union,
     cast,
 )
 
@@ -1778,10 +1777,6 @@ def expand_start_trigger_args(self, *, context: Context, session: Session) -> St
         return self.start_trigger_args
 
 
-# TODO: Deprecate for Airflow 3.0
-Chainable = Union[DependencyMixin, Sequence[DependencyMixin]]
-
-
 def chain(*tasks: DependencyMixin | Sequence[DependencyMixin]) -> None:
     r"""
     Given a number of tasks, builds a dependency chain.