diff --git a/homeassistant/components/hive/config_flow.py b/homeassistant/components/hive/config_flow.py
index e5b6fe88b63f..60a394cc0197 100644
--- a/homeassistant/components/hive/config_flow.py
+++ b/homeassistant/components/hive/config_flow.py
@@ -50,12 +50,14 @@ class HiveFlowHandler(ConfigFlow, domain=DOMAIN):
         # Login to Hive with user data.
         if user_input is not None:
             self.data.update(user_input)
+            username = self.data[CONF_USERNAME].lower()
             self.hive_auth = Auth(
-                username=self.data[CONF_USERNAME], password=self.data[CONF_PASSWORD]
+                username=username,
+                password=self.data[CONF_PASSWORD],
             )
 
             # Get user from existing entry and abort if already setup
-            await self.async_set_unique_id(self.data[CONF_USERNAME])
+            await self.async_set_unique_id(username)
             if self.context["source"] != SOURCE_REAUTH:
                 self._abort_if_unique_id_configured()
 
diff --git a/tests/components/hive/test_config_flow.py b/tests/components/hive/test_config_flow.py
index fdfece06dd9d..a9addf59e32a 100644
--- a/tests/components/hive/test_config_flow.py
+++ b/tests/components/hive/test_config_flow.py
@@ -1,8 +1,9 @@
 """Test the Hive config flow."""
 
-from unittest.mock import patch
+from unittest.mock import AsyncMock, patch
 
 from apyhiveapi.helper import hive_exceptions
+import pytest
 
 from homeassistant import config_entries
 from homeassistant.components.hive.const import CONF_CODE, CONF_DEVICE_NAME, DOMAIN
@@ -25,8 +26,13 @@ MFA_RESEND_CODE = "0000"
 MFA_INVALID_CODE = "HIVE"
 
 
-async def test_user_flow(hass: HomeAssistant) -> None:
-    """Test the user flow."""
+@pytest.mark.parametrize(
+    "username",
+    [USERNAME, USERNAME.upper()],
+    ids=["lowercase", "uppercase"],
+)
+async def test_user_flow(hass: HomeAssistant, username: str) -> None:
+    """Test the user flow normalizes the username for Hive auth."""
     result = await hass.config_entries.flow.async_init(
         DOMAIN, context={"source": config_entries.SOURCE_USER}
     )
@@ -35,31 +41,31 @@ async def test_user_flow(hass: HomeAssistant) -> None:
     assert result["errors"] == {}
 
     with (
+        patch("homeassistant.components.hive.config_flow.Auth") as mock_auth,
         patch(
-            "homeassistant.components.hive.config_flow.Auth.login",
+            "homeassistant.components.hive.async_setup_entry",
+            return_value=True,
+        ) as mock_setup_entry,
+    ):
+        mock_auth.return_value.login = AsyncMock(
             return_value={
                 "ChallengeName": "SUCCESS",
                 "AuthenticationResult": {
                     "RefreshToken": "mock-refresh-token",
                     "AccessToken": "mock-access-token",
                 },
-            },
-        ),
-        patch(
-            "homeassistant.components.hive.async_setup_entry",
-            return_value=True,
-        ) as mock_setup_entry,
-    ):
+            }
+        )
         result = await hass.config_entries.flow.async_configure(
             result["flow_id"],
-            {CONF_USERNAME: USERNAME, CONF_PASSWORD: PASSWORD},
+            {CONF_USERNAME: username, CONF_PASSWORD: PASSWORD},
         )
         await hass.async_block_till_done()
 
     assert result["type"] is FlowResultType.CREATE_ENTRY
-    assert result["title"] == USERNAME
+    assert result["title"] == username
     assert result["data"] == {
-        CONF_USERNAME: USERNAME,
+        CONF_USERNAME: username,
         CONF_PASSWORD: PASSWORD,
         "tokens": {
             "AuthenticationResult": {
@@ -69,9 +75,10 @@ async def test_user_flow(hass: HomeAssistant) -> None:
             "ChallengeName": "SUCCESS",
         },
     }
-
+    assert mock_auth.call_args.kwargs["username"] == username.lower()
     assert len(mock_setup_entry.mock_calls) == 1
     assert len(hass.config_entries.async_entries(DOMAIN)) == 1
+    assert hass.config_entries.async_entries(DOMAIN)[0].unique_id == username.lower()
 
 
 async def test_user_flow_with_no_2fa(hass: HomeAssistant) -> None:
@@ -734,7 +741,7 @@ async def test_abort_if_existing_entry(hass: HomeAssistant) -> None:
         DOMAIN,
         context={"source": config_entries.SOURCE_USER},
         data={
-            CONF_USERNAME: USERNAME,
+            CONF_USERNAME: USERNAME.upper(),
             CONF_PASSWORD: PASSWORD,
         },
     )