diff --git a/src/pytorch_lightning/CHANGELOG.md b/src/pytorch_lightning/CHANGELOG.md
index 4b5e3a893429e..0351719fefa89 100644
--- a/src/pytorch_lightning/CHANGELOG.md
+++ b/src/pytorch_lightning/CHANGELOG.md
@@ -81,10 +81,13 @@ The format is based on [Keep a Changelog](http://keepachangelog.com/en/1.0.0/).
 - Removed the deprecated `DistributedType` and `DeviceType` enum classes ([#14045](https://github.com/Lightning-AI/lightning/pull/14045))
 
 
-- Remove the deprecated `on_train_batch_end(outputs)` format when multiple optimizers are used and TBPTT is enabled ([#14373](https://github.com/PyTorchLightning/pytorch-lightning/pull/14373))
+- Removed the legacy and unused `Trainer.get_deprecated_arg_names()` ([#14415](https://github.com/Lightning-AI/lightning/pull/14415))
 
 
-- Remove the deprecated  `training_epoch_end(outputs)` format when multiple optimizers are used and TBPTT is enabled ([#14373](https://github.com/PyTorchLightning/pytorch-lightning/pull/14373))
+- Removed the deprecated `on_train_batch_end(outputs)` format when multiple optimizers are used and TBPTT is enabled ([#14373](https://github.com/PyTorchLightning/pytorch-lightning/pull/14373))
+
+
+- Removed the deprecated  `training_epoch_end(outputs)` format when multiple optimizers are used and TBPTT is enabled ([#14373](https://github.com/PyTorchLightning/pytorch-lightning/pull/14373))
 
 
 - Removed the experimental `pytorch_lightning.utiltiies.meta` functions in favor of built-in https://github.com/pytorch/torchdistx support ([#13868](https://github.com/Lightning-AI/lightning/pull/13868))
diff --git a/src/pytorch_lightning/core/datamodule.py b/src/pytorch_lightning/core/datamodule.py
index b7a25badf420f..e4adf9b1ca928 100644
--- a/src/pytorch_lightning/core/datamodule.py
+++ b/src/pytorch_lightning/core/datamodule.py
@@ -113,15 +113,6 @@ def get_init_arguments_and_types(cls) -> List[Tuple[str, Tuple, Any]]:
         """
         return get_init_arguments_and_types(cls)
 
-    @classmethod
-    def get_deprecated_arg_names(cls) -> List:
-        """Returns a list with deprecated DataModule arguments."""
-        depr_arg_names: List[str] = []
-        for name, val in cls.__dict__.items():
-            if name.startswith("DEPRECATED") and isinstance(val, (tuple, list)):
-                depr_arg_names.extend(val)
-        return depr_arg_names
-
     @classmethod
     def from_datasets(
         cls,
diff --git a/src/pytorch_lightning/trainer/trainer.py b/src/pytorch_lightning/trainer/trainer.py
index d5bcec7db85d6..08561b2e77417 100644
--- a/src/pytorch_lightning/trainer/trainer.py
+++ b/src/pytorch_lightning/trainer/trainer.py
@@ -2434,15 +2434,6 @@ def default_attributes(cls) -> dict:
         init_signature = inspect.signature(cls)
         return {k: v.default for k, v in init_signature.parameters.items()}
 
-    @classmethod
-    def get_deprecated_arg_names(cls) -> List:
-        """Returns a list with deprecated Trainer arguments."""
-        depr_arg_names = []
-        for name, val in cls.__dict__.items():
-            if name.startswith("DEPRECATED") and isinstance(val, (tuple, list)):
-                depr_arg_names.extend(val)
-        return depr_arg_names
-
     @classmethod
     def from_argparse_args(cls: Any, args: Union[Namespace, ArgumentParser], **kwargs) -> Any:
         return from_argparse_args(cls, args, **kwargs)
diff --git a/src/pytorch_lightning/utilities/argparse.py b/src/pytorch_lightning/utilities/argparse.py
index 26277db183410..8b1872ee7b643 100644
--- a/src/pytorch_lightning/utilities/argparse.py
+++ b/src/pytorch_lightning/utilities/argparse.py
@@ -212,8 +212,6 @@ def add_argparse_args(
         parser = ArgumentParser(parents=[parent_parser], add_help=False)
 
     ignore_arg_names = ["self", "args", "kwargs"]
-    if hasattr(cls, "get_deprecated_arg_names"):
-        ignore_arg_names += cls.get_deprecated_arg_names()
 
     allowed_types = (str, int, float, bool)
 
diff --git a/tests/tests_pytorch/utilities/test_argparse.py b/tests/tests_pytorch/utilities/test_argparse.py
index 2a88e8db531f9..ba5d51c2a2095 100644
--- a/tests/tests_pytorch/utilities/test_argparse.py
+++ b/tests/tests_pytorch/utilities/test_argparse.py
@@ -1,6 +1,6 @@
 import io
 from argparse import ArgumentParser, Namespace
-from typing import Generic, List, TypeVar
+from typing import Generic, TypeVar
 from unittest.mock import MagicMock
 
 import pytest
@@ -118,10 +118,6 @@ class AddArgparseArgsExampleClass:
     def __init__(self, my_parameter: int = 0):
         pass
 
-    @staticmethod
-    def get_deprecated_arg_names() -> List[str]:
-        return []
-
 
 class AddArgparseArgsExampleClassViaInit:
     def __init__(self, my_parameter: int = 0):