diff --git a/src/lightning/pytorch/CHANGELOG.md b/src/lightning/pytorch/CHANGELOG.md
index 9f7317c218c30..78beedb72b5bf 100644
--- a/src/lightning/pytorch/CHANGELOG.md
+++ b/src/lightning/pytorch/CHANGELOG.md
@@ -4,6 +4,10 @@ All notable changes to this project will be documented in this file.
 
 The format is based on [Keep a Changelog](http://keepachangelog.com/en/1.0.0/).
 
+## [Unreleased]
+
+- Added support for MPS mixed-precision autocast ([#20531](https://github.com/Lightning-AI/pytorch-lightning/pull/20531))
+
 ## [2.5.0] - 2024-12-19
 
 ### Added
diff --git a/src/lightning/pytorch/trainer/connectors/accelerator_connector.py b/src/lightning/pytorch/trainer/connectors/accelerator_connector.py
index 40ee0eef4de33..079791d2f3fc7 100644
--- a/src/lightning/pytorch/trainer/connectors/accelerator_connector.py
+++ b/src/lightning/pytorch/trainer/connectors/accelerator_connector.py
@@ -520,7 +520,7 @@ def _check_and_init_precision(self) -> Precision:
             rank_zero_info(
                 f"Using {'16bit' if self._precision_flag == '16-mixed' else 'bfloat16'} Automatic Mixed Precision (AMP)"
             )
-            device = "cpu" if self._accelerator_flag == "cpu" else "cuda"
+            device = "cpu" if self._accelerator_flag == "cpu" else "mps" if self._accelerator_flag == "mps" else "cuda"
             return MixedPrecision(self._precision_flag, device)  # type: ignore[arg-type]
 
         raise RuntimeError("No precision set")