diff --git a/homeassistant/components/thread/discovery.py b/homeassistant/components/thread/discovery.py
index b2373ff9825..7dce5a429d8 100644
--- a/homeassistant/components/thread/discovery.py
+++ b/homeassistant/components/thread/discovery.py
@@ -32,6 +32,7 @@ class ThreadRouterDiscoveryData:
 
     addresses: list[str] | None
     brand: str | None
+    extended_address: str | None
     extended_pan_id: str | None
     model_name: str | None
     network_name: str | None
@@ -55,6 +56,7 @@ def async_discovery_data_from_service(
         except UnicodeDecodeError:
             return None
 
+    ext_addr = service.properties.get(b"xa")
     ext_pan_id = service.properties.get(b"xp")
     network_name = try_decode(service.properties.get(b"nn"))
     model_name = try_decode(service.properties.get(b"mn"))
@@ -78,6 +80,7 @@ def async_discovery_data_from_service(
     return ThreadRouterDiscoveryData(
         addresses=service.parsed_addresses(),
         brand=brand,
+        extended_address=ext_addr.hex() if ext_addr is not None else None,
         extended_pan_id=ext_pan_id.hex() if ext_pan_id is not None else None,
         model_name=model_name,
         network_name=network_name,
diff --git a/tests/components/thread/test_discovery.py b/tests/components/thread/test_discovery.py
index e832f18c4e6..84fe4c30974 100644
--- a/tests/components/thread/test_discovery.py
+++ b/tests/components/thread/test_discovery.py
@@ -73,6 +73,7 @@ async def test_discover_routers(hass: HomeAssistant, mock_async_zeroconf: None)
         discovery.ThreadRouterDiscoveryData(
             addresses=["192.168.0.115"],
             brand="homeassistant",
+            extended_address="aeeb2f594b570bbf",
             extended_pan_id="e60fc7c186212ce5",
             model_name="OpenThreadBorderRouter",
             network_name="OpenThread HC",
@@ -98,6 +99,7 @@ async def test_discover_routers(hass: HomeAssistant, mock_async_zeroconf: None)
         discovery.ThreadRouterDiscoveryData(
             addresses=["192.168.0.124"],
             brand="google",
+            extended_address="f6a99b425a67abed",
             extended_pan_id="9e75e256f61409a3",
             model_name="Google Nest Hub",
             network_name="NEST-PAN-E1AF",
@@ -175,6 +177,7 @@ async def test_discover_routers_unconfigured(
         discovery.ThreadRouterDiscoveryData(
             addresses=["192.168.0.115"],
             brand="homeassistant",
+            extended_address="aeeb2f594b570bbf",
             extended_pan_id="e60fc7c186212ce5",
             model_name="OpenThreadBorderRouter",
             network_name="OpenThread HC",
@@ -219,6 +222,7 @@ async def test_discover_routers_bad_data(
         discovery.ThreadRouterDiscoveryData(
             addresses=["192.168.0.115"],
             brand=None,
+            extended_address="aeeb2f594b570bbf",
             extended_pan_id="e60fc7c186212ce5",
             model_name="OpenThreadBorderRouter",
             network_name="OpenThread HC",
diff --git a/tests/components/thread/test_websocket_api.py b/tests/components/thread/test_websocket_api.py
index 0f3a2ff7654..f8f09b0b8cc 100644
--- a/tests/components/thread/test_websocket_api.py
+++ b/tests/components/thread/test_websocket_api.py
@@ -236,6 +236,7 @@ async def test_discover_routers(
             "data": {
                 "addresses": ["192.168.0.115"],
                 "brand": "homeassistant",
+                "extended_address": "aeeb2f594b570bbf",
                 "extended_pan_id": "e60fc7c186212ce5",
                 "model_name": "OpenThreadBorderRouter",
                 "network_name": "OpenThread HC",
@@ -264,6 +265,7 @@ async def test_discover_routers(
             "data": {
                 "addresses": ["192.168.0.124"],
                 "brand": "google",
+                "extended_address": "f6a99b425a67abed",
                 "extended_pan_id": "9e75e256f61409a3",
                 "model_name": "Google Nest Hub",
                 "network_name": "NEST-PAN-E1AF",