diff --git a/homeassistant/components/cast/media_player.py b/homeassistant/components/cast/media_player.py
index 837284ab546..e63fedd3598 100644
--- a/homeassistant/components/cast/media_player.py
+++ b/homeassistant/components/cast/media_player.py
@@ -10,7 +10,12 @@ import logging
 
 import pychromecast
 from pychromecast.controllers.homeassistant import HomeAssistantController
-from pychromecast.controllers.media import MEDIA_PLAYER_ERROR_CODES
+from pychromecast.controllers.media import (
+    MEDIA_PLAYER_ERROR_CODES,
+    MEDIA_PLAYER_STATE_BUFFERING,
+    MEDIA_PLAYER_STATE_PLAYING,
+    MEDIA_PLAYER_STATE_UNKNOWN,
+)
 from pychromecast.controllers.multizone import MultizoneManager
 from pychromecast.controllers.receiver import VOLUME_CONTROL_TYPE_FIXED
 from pychromecast.quick_play import quick_play
@@ -40,6 +45,7 @@ from homeassistant.config_entries import ConfigEntry
 from homeassistant.const import (
     CAST_APP_ID_HOMEASSISTANT_LOVELACE,
     EVENT_HOMEASSISTANT_STOP,
+    STATE_BUFFERING,
     STATE_IDLE,
     STATE_OFF,
     STATE_PAUSED,
@@ -453,10 +459,13 @@ class CastMediaPlayerEntity(CastDevice, MediaPlayerEntity):
         media_status = self.media_status
         media_controller = self._chromecast.media_controller
 
-        if media_status is None or media_status.player_state == "UNKNOWN":
+        if (
+            media_status is None
+            or media_status.player_state == MEDIA_PLAYER_STATE_UNKNOWN
+        ):
             groups = self.mz_media_status
             for k, val in groups.items():
-                if val and val.player_state != "UNKNOWN":
+                if val and val.player_state != MEDIA_PLAYER_STATE_UNKNOWN:
                     media_controller = self.mz_mgr.get_multizone_mediacontroller(k)
                     break
 
@@ -716,10 +725,13 @@ class CastMediaPlayerEntity(CastDevice, MediaPlayerEntity):
         media_status = self.media_status
         media_status_received = self.media_status_received
 
-        if media_status is None or media_status.player_state == "UNKNOWN":
+        if (
+            media_status is None
+            or media_status.player_state == MEDIA_PLAYER_STATE_UNKNOWN
+        ):
             groups = self.mz_media_status
             for k, val in groups.items():
-                if val and val.player_state != "UNKNOWN":
+                if val and val.player_state != MEDIA_PLAYER_STATE_UNKNOWN:
                     media_status = val
                     media_status_received = self.mz_media_status_received[k]
                     break
@@ -733,8 +745,10 @@ class CastMediaPlayerEntity(CastDevice, MediaPlayerEntity):
         if self.app_id == CAST_APP_ID_HOMEASSISTANT_LOVELACE:
             return STATE_PLAYING
         if (media_status := self._media_status()[0]) is not None:
-            if media_status.player_is_playing:
+            if media_status.player_state == MEDIA_PLAYER_STATE_PLAYING:
                 return STATE_PLAYING
+            if media_status.player_state == MEDIA_PLAYER_STATE_BUFFERING:
+                return STATE_BUFFERING
             if media_status.player_is_paused:
                 return STATE_PAUSED
             if media_status.player_is_idle:
diff --git a/homeassistant/const.py b/homeassistant/const.py
index b2654da367a..ffe5825bf89 100644
--- a/homeassistant/const.py
+++ b/homeassistant/const.py
@@ -323,6 +323,7 @@ STATE_OPEN: Final = "open"
 STATE_OPENING: Final = "opening"
 STATE_CLOSED: Final = "closed"
 STATE_CLOSING: Final = "closing"
+STATE_BUFFERING: Final = "buffering"
 STATE_PLAYING: Final = "playing"
 STATE_PAUSED: Final = "paused"
 STATE_IDLE: Final = "idle"
diff --git a/tests/components/cast/test_media_player.py b/tests/components/cast/test_media_player.py
index 063490e6e13..88cf281c8a5 100644
--- a/tests/components/cast/test_media_player.py
+++ b/tests/components/cast/test_media_player.py
@@ -1257,6 +1257,7 @@ async def test_entity_control(hass: HomeAssistant, quick_play_mock):
 
     # Fake media status
     media_status = MagicMock(images=None)
+    media_status.player_state = "PLAYING"
     media_status.supports_queue_next = False
     media_status.supports_seek = False
     media_status_cb(media_status)
@@ -1397,13 +1398,19 @@ async def test_entity_media_states(hass: HomeAssistant, app_id, state_no_media):
 
     # Got media status
     media_status = MagicMock(images=None)
-    media_status.player_is_playing = True
+    media_status.player_state = "BUFFERING"
+    media_status_cb(media_status)
+    await hass.async_block_till_done()
+    state = hass.states.get(entity_id)
+    assert state.state == "buffering"
+
+    media_status.player_state = "PLAYING"
     media_status_cb(media_status)
     await hass.async_block_till_done()
     state = hass.states.get(entity_id)
     assert state.state == "playing"
 
-    media_status.player_is_playing = False
+    media_status.player_state = None
     media_status.player_is_paused = True
     media_status_cb(media_status)
     await hass.async_block_till_done()
@@ -1536,15 +1543,22 @@ async def test_group_media_states(hass, mz_mock):
     group_media_status = MagicMock(images=None)
     player_media_status = MagicMock(images=None)
 
+    # Player has no state, group is buffering -> Should report 'buffering'
+    group_media_status.player_state = "BUFFERING"
+    group_media_status_cb(str(FakeGroupUUID), group_media_status)
+    await hass.async_block_till_done()
+    state = hass.states.get(entity_id)
+    assert state.state == "buffering"
+
     # Player has no state, group is playing -> Should report 'playing'
-    group_media_status.player_is_playing = True
+    group_media_status.player_state = "PLAYING"
     group_media_status_cb(str(FakeGroupUUID), group_media_status)
     await hass.async_block_till_done()
     state = hass.states.get(entity_id)
     assert state.state == "playing"
 
     # Player is paused, group is playing -> Should report 'paused'
-    player_media_status.player_is_playing = False
+    player_media_status.player_state = None
     player_media_status.player_is_paused = True
     media_status_cb(player_media_status)
     await hass.async_block_till_done()