diff --git a/CHANGELOG.md b/CHANGELOG.md
index 400fe58b4eaee..a4a66f1157ff7 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -63,6 +63,9 @@ The format is based on [Keep a Changelog](http://keepachangelog.com/en/1.0.0/).
 - Removed the deprecated `summarize` method from the `LightningModule` ([#12559](https://github.com/PyTorchLightning/pytorch-lightning/pull/12559))
 
 
+- Removed the deprecated `model_size` property from the `LightningModule` class ([#12641](https://github.com/PyTorchLightning/pytorch-lightning/pull/12641))
+
+
 - Removed the deprecated `stochastic_weight_avg` argument from the `Trainer` constructor ([#12535](https://github.com/PyTorchLightning/pytorch-lightning/pull/12535))
 
 
diff --git a/docs/source/common/lightning_module.rst b/docs/source/common/lightning_module.rst
index fd9de11f601d8..9b94417abdc95 100644
--- a/docs/source/common/lightning_module.rst
+++ b/docs/source/common/lightning_module.rst
@@ -1112,11 +1112,6 @@ Set and access example_input_array, which basically represents a single batch.
         # generate some images using the example_input_array
         gen_images = self.generator(self.example_input_array)
 
-model_size
-~~~~~~~~~~
-
-Get the model file size (in megabytes) using ``self.model_size`` inside LightningModule.
-
 truncated_bptt_steps
 ~~~~~~~~~~~~~~~~~~~~
 
diff --git a/pytorch_lightning/core/lightning.py b/pytorch_lightning/core/lightning.py
index ef162374318d1..93d2a7d6f8999 100644
--- a/pytorch_lightning/core/lightning.py
+++ b/pytorch_lightning/core/lightning.py
@@ -45,7 +45,6 @@
 from pytorch_lightning.utilities.cloud_io import get_filesystem
 from pytorch_lightning.utilities.distributed import distributed_available, sync_ddp
 from pytorch_lightning.utilities.exceptions import MisconfigurationException
-from pytorch_lightning.utilities.memory import get_model_size_mb
 from pytorch_lightning.utilities.parsing import collect_init_args
 from pytorch_lightning.utilities.rank_zero import rank_zero_debug, rank_zero_deprecation, rank_zero_warn
 from pytorch_lightning.utilities.signature_utils import is_param_in_hook_signature
@@ -77,7 +76,6 @@ class LightningModule(
             "local_rank",
             "logger",
             "loggers",
-            "model_size",
             "automatic_optimization",
             "truncated_bptt_steps",
             "use_amp",
@@ -1928,21 +1926,6 @@ def to_torchscript(
 
         return torchscript_module
 
-    @property
-    def model_size(self) -> float:
-        """Returns the model size in MegaBytes (MB)
-
-        Note:
-            This property will not return correct value for Deepspeed (stage 3) and fully-sharded training.
-        """
-        if not self._running_torchscript:  # remove with the deprecation removal
-            rank_zero_deprecation(
-                "The `LightningModule.model_size` property was deprecated in v1.5 and will be removed in v1.7."
-                " Please use the `pytorch_lightning.utilities.memory.get_model_size_mb`.",
-                stacklevel=5,
-            )
-        return get_model_size_mb(self)
-
     @property
     def use_amp(self) -> bool:
         r"""
diff --git a/tests/deprecated_api/test_remove_1-7.py b/tests/deprecated_api/test_remove_1-7.py
index 167b3095d91b0..7525054f14452 100644
--- a/tests/deprecated_api/test_remove_1-7.py
+++ b/tests/deprecated_api/test_remove_1-7.py
@@ -57,14 +57,6 @@ def test_v1_7_0_moved_get_memory_profile_and_get_gpu_memory_map(tmpdir):
         from pytorch_lightning.core.memory import get_gpu_memory_map, get_memory_profile  # noqa: F401
 
 
-def test_v1_7_0_deprecated_model_size():
-    model = BoringModel()
-    with pytest.deprecated_call(
-        match="LightningModule.model_size` property was deprecated in v1.5 and will be removed in v1.7"
-    ):
-        _ = model.model_size
-
-
 def test_v1_7_0_datamodule_transform_properties(tmpdir):
     dm = MNISTDataModule()
     with pytest.deprecated_call(match=r"DataModule property `train_transforms` was deprecated in v1.5"):