diff --git a/homeassistant/components/plex/media_player.py b/homeassistant/components/plex/media_player.py
index 003ad23f977..cd94bb49632 100644
--- a/homeassistant/components/plex/media_player.py
+++ b/homeassistant/components/plex/media_player.py
@@ -109,8 +109,10 @@ class PlexMediaPlayer(MediaPlayerDevice):
         self._is_player_active = False
         self._machine_identifier = device.machineIdentifier
         self._make = ""
+        self._device_platform = None
         self._device_product = None
         self._device_title = None
+        self._device_version = None
         self._name = None
         self._player_state = "idle"
         self._previous_volume_level = 1  # Used in fake muting
@@ -195,8 +197,10 @@ class PlexMediaPlayer(MediaPlayerDevice):
                 device_url = "127.0.0.1"
             if "127.0.0.1" in device_url:
                 self.device.proxyThroughServer()
+            self._device_platform = self.device.platform
             self._device_product = self.device.product
             self._device_title = self.device.title
+            self._device_version = self.device.version
             self._device_protocol_capabilities = self.device.protocolCapabilities
             self._player_state = self.device.state
 
@@ -216,6 +220,7 @@ class PlexMediaPlayer(MediaPlayerDevice):
                 self._player_state = session_device.state
                 self._device_product = self._device_product or session_device.product
                 self._device_title = self._device_title or session_device.title
+                self._device_version = self._device_version or session_device.version
             else:
                 _LOGGER.warning("No player associated with active session")
 
@@ -724,3 +729,18 @@ class PlexMediaPlayer(MediaPlayerDevice):
         }
 
         return attr
+
+    @property
+    def device_info(self):
+        """Return a device description for device registry."""
+        if self.machine_identifier is None:
+            return None
+
+        return {
+            "identifiers": {(PLEX_DOMAIN, self.machine_identifier)},
+            "manufacturer": "Plex",
+            "model": self._device_product or self._device_platform or self.make,
+            "name": self.name,
+            "sw_version": self._device_version,
+            "via_device": (PLEX_DOMAIN, self.plex_server.machine_identifier),
+        }
diff --git a/homeassistant/components/plex/sensor.py b/homeassistant/components/plex/sensor.py
index 4fe6ed444ef..1caf8ec5f75 100644
--- a/homeassistant/components/plex/sensor.py
+++ b/homeassistant/components/plex/sensor.py
@@ -142,3 +142,17 @@ class PlexSensor(Entity):
             now_playing.append((now_playing_user, now_playing_title))
         self._state = len(self.sessions)
         self._now_playing = now_playing
+
+    @property
+    def device_info(self):
+        """Return a device description for device registry."""
+        if self.unique_id is None:
+            return None
+
+        return {
+            "identifiers": {(PLEX_DOMAIN, self._server.machine_identifier)},
+            "manufacturer": "Plex",
+            "model": "Plex Media Server",
+            "name": "Activity Sensor",
+            "sw_version": self._server.version,
+        }
diff --git a/homeassistant/components/plex/server.py b/homeassistant/components/plex/server.py
index fcc7e5dda17..fe453ef2e9e 100644
--- a/homeassistant/components/plex/server.py
+++ b/homeassistant/components/plex/server.py
@@ -52,6 +52,7 @@ class PlexServer:
         self.options = options
         self.server_choice = None
         self._owner_username = None
+        self._version = None
 
         # Header conditionally added as it is not available in config entry v1
         if CONF_CLIENT_IDENTIFIER in server_config:
@@ -102,6 +103,8 @@ class PlexServer:
         if owner_account:
             self._owner_username = owner_account[0]
 
+        self._version = self._plex_server.version
+
     def refresh_entity(self, machine_identifier, device, session):
         """Forward refresh dispatch to media_player."""
         unique_id = f"{self.machine_identifier}:{machine_identifier}"
@@ -196,6 +199,11 @@ class PlexServer:
         """Return the Plex server owner username."""
         return self._owner_username
 
+    @property
+    def version(self):
+        """Return the version of the Plex server."""
+        return self._version
+
     @property
     def friendly_name(self):
         """Return name of connected Plex server."""
diff --git a/tests/components/plex/mock_classes.py b/tests/components/plex/mock_classes.py
index ed354138cb2..c4fccb35bb0 100644
--- a/tests/components/plex/mock_classes.py
+++ b/tests/components/plex/mock_classes.py
@@ -87,3 +87,8 @@ class MockPlexServer:
     def url_in_use(self):
         """Return URL used by PlexServer."""
         return self._baseurl
+
+    @property
+    def version(self):
+        """Mock version of PlexServer."""
+        return "1.0"