diff --git a/homeassistant/components/velbus/diagnostics.py b/homeassistant/components/velbus/diagnostics.py
index 04f240e3cf31..158c82779bf7 100644
--- a/homeassistant/components/velbus/diagnostics.py
+++ b/homeassistant/components/velbus/diagnostics.py
@@ -29,6 +29,7 @@ async def _build_module_diagnostics_info(module: VelbusModule) -> dict[str, Any]
         "name": module.get_name(),
         "sw_version": module.get_sw_version(),
         "is_loaded": await module.is_loaded(),
+        "serial": module.get_serial(),
         "channels": _build_channels_diagnostics_info(module.get_channels()),
     }
     return data
diff --git a/tests/components/velbus/snapshots/test_diagnostics.ambr b/tests/components/velbus/snapshots/test_diagnostics.ambr
index 6667c8a35086..f45594deabf1 100644
--- a/tests/components/velbus/snapshots/test_diagnostics.ambr
+++ b/tests/components/velbus/snapshots/test_diagnostics.ambr
@@ -34,6 +34,7 @@
         }),
         'is_loaded': True,
         'name': 'BedRoom',
+        'serial': 'a1b2c3d4e5f6',
         'sw_version': '1.0.0',
         'type': 'VMB4RYLD',
       }),
@@ -48,6 +49,7 @@
         }),
         'is_loaded': True,
         'name': 'BedRoom',
+        'serial': 'a1b2c3d4e5f6',
         'sw_version': '1.0.0',
         'type': 'VMB4RYLD',
       }),
@@ -62,6 +64,7 @@
         }),
         'is_loaded': True,
         'name': 'BedRoom',
+        'serial': 'a1b2c3d4e5f6',
         'sw_version': '1.0.0',
         'type': 'VMB4RYLD',
       }),
@@ -76,6 +79,7 @@
         }),
         'is_loaded': True,
         'name': 'BedRoom',
+        'serial': 'a1b2c3d4e5f6',
         'sw_version': '1.0.0',
         'type': 'VMB4RYLD',
       }),
@@ -87,6 +91,7 @@
         }),
         'is_loaded': True,
         'name': 'Kitchen',
+        'serial': 'a1b2c3d4e5f6',
         'sw_version': '2.0.0',
         'type': 'VMB2BLE',
       }),