diff --git a/homeassistant/components/geniushub/__init__.py b/homeassistant/components/geniushub/__init__.py
index d750282b4f1..18580f331d2 100644
--- a/homeassistant/components/geniushub/__init__.py
+++ b/homeassistant/components/geniushub/__init__.py
@@ -155,8 +155,22 @@ type GeniusHubConfigEntry = ConfigEntry[GeniusBroker]
 
 async def async_setup_entry(hass: HomeAssistant, entry: GeniusHubConfigEntry) -> bool:
     """Create a Genius Hub system."""
+    if CONF_TOKEN in entry.data and CONF_MAC in entry.data:
+        entity_registry = er.async_get(hass)
+        registry_entries = er.async_entries_for_config_entry(
+            entity_registry, entry.entry_id
+        )
+        for reg_entry in registry_entries:
+            if reg_entry.unique_id.startswith(entry.data[CONF_MAC]):
+                entity_registry.async_update_entity(
+                    reg_entry.entity_id,
+                    new_unique_id=reg_entry.unique_id.replace(
+                        entry.data[CONF_MAC], entry.entry_id
+                    ),
+                )
 
     session = async_get_clientsession(hass)
+    unique_id: str
     if CONF_HOST in entry.data:
         client = GeniusHub(
             entry.data[CONF_HOST],
@@ -164,14 +178,12 @@ async def async_setup_entry(hass: HomeAssistant, entry: GeniusHubConfigEntry) ->
             password=entry.data[CONF_PASSWORD],
             session=session,
         )
+        unique_id = entry.data[CONF_MAC]
     else:
         client = GeniusHub(entry.data[CONF_TOKEN], session=session)
+        unique_id = entry.entry_id
 
-    unique_id = entry.unique_id or entry.entry_id
-
-    broker = entry.runtime_data = GeniusBroker(
-        hass, client, entry.data.get(CONF_MAC, unique_id)
-    )
+    broker = entry.runtime_data = GeniusBroker(hass, client, unique_id)
 
     try:
         await client.update()
diff --git a/tests/components/geniushub/test_init.py b/tests/components/geniushub/test_init.py
new file mode 100644
index 00000000000..ebdc082c4b8
--- /dev/null
+++ b/tests/components/geniushub/test_init.py
@@ -0,0 +1,39 @@
+"""Tests for the Genius Hub component."""
+
+from unittest.mock import AsyncMock
+
+from homeassistant.components.geniushub import DOMAIN
+from homeassistant.components.sensor import DOMAIN as SENSOR_DOMAIN
+from homeassistant.const import CONF_MAC, CONF_TOKEN
+from homeassistant.core import HomeAssistant
+from homeassistant.helpers import entity_registry as er
+
+from tests.common import MockConfigEntry
+
+
+async def test_cloud_unique_id_migration(
+    hass: HomeAssistant,
+    entity_registry: er.EntityRegistry,
+    mock_geniushub_cloud: AsyncMock,
+) -> None:
+    """Test that the cloud unique ID is migrated to the entry_id."""
+    entry = MockConfigEntry(
+        domain=DOMAIN,
+        title="Genius hub",
+        data={
+            CONF_TOKEN: "abcdef",
+            CONF_MAC: "aa:bb:cc:dd:ee:ff",
+        },
+        entry_id="1234",
+    )
+    entry.add_to_hass(hass)
+    entity_registry.async_get_or_create(
+        SENSOR_DOMAIN, DOMAIN, "aa:bb:cc:dd:ee:ff_device_78", config_entry=entry
+    )
+    await hass.config_entries.async_setup(entry.entry_id)
+    await hass.async_block_till_done()
+    assert hass.states.get("sensor.geniushub_aa_bb_cc_dd_ee_ff_device_78")
+    entity_entry = entity_registry.async_get(
+        "sensor.geniushub_aa_bb_cc_dd_ee_ff_device_78"
+    )
+    assert entity_entry.unique_id == "1234_device_78"