diff --git a/homeassistant/components/imou/config_flow.py b/homeassistant/components/imou/config_flow.py
index a00b7bf5ffe8..8eddc540357d 100644
--- a/homeassistant/components/imou/config_flow.py
+++ b/homeassistant/components/imou/config_flow.py
@@ -1,5 +1,6 @@
 """Config flow for Imou."""
 
+from collections.abc import Mapping
 import logging
 from typing import Any, override
 
@@ -17,12 +18,26 @@ from homeassistant.helpers.selector import (
     SelectSelector,
     SelectSelectorConfig,
     SelectSelectorMode,
+    TextSelector,
+    TextSelectorConfig,
+    TextSelectorType,
 )
 
 from .const import API_URLS, CONF_API_URL, CONF_APP_ID, CONF_APP_SECRET, DOMAIN
 
 _LOGGER = logging.getLogger(__name__)
 
+REAUTH_SCHEMA = vol.Schema(
+    {
+        vol.Required(CONF_APP_SECRET): TextSelector(
+            TextSelectorConfig(
+                type=TextSelectorType.PASSWORD,
+                autocomplete="current-password",
+            )
+        ),
+    }
+)
+
 
 class ImouConfigFlow(ConfigFlow, domain=DOMAIN):
     """Config flow for Imou integration."""
@@ -30,6 +45,27 @@ class ImouConfigFlow(ConfigFlow, domain=DOMAIN):
     VERSION = 1
     MINOR_VERSION = 1
 
+    async def _validate_input(self, user_input: dict[str, Any]) -> dict[str, str]:
+        """Validate credentials and close the temporary client."""
+        errors: dict[str, str] = {}
+        api_client = ImouOpenApiClient(
+            user_input[CONF_APP_ID],
+            user_input[CONF_APP_SECRET],
+            API_URLS[user_input[CONF_API_URL]],
+        )
+        try:
+            await api_client.async_get_token()
+        except InvalidAppIdOrSecretException:
+            errors["base"] = "invalid_auth"
+        except ConnectFailedException, RequestFailedException:
+            errors["base"] = "cannot_connect"
+        except ImouException as exception:
+            _LOGGER.debug("Imou error during config flow: %s", exception)
+            errors["base"] = "unknown"
+        finally:
+            await api_client.async_close()
+        return errors
+
     @override
     async def async_step_user(
         self, user_input: dict[str, Any] | None = None
@@ -39,21 +75,7 @@ class ImouConfigFlow(ConfigFlow, domain=DOMAIN):
         if user_input is not None:
             await self.async_set_unique_id(user_input[CONF_APP_ID])
             self._abort_if_unique_id_configured()
-            api_client = ImouOpenApiClient(
-                user_input[CONF_APP_ID],
-                user_input[CONF_APP_SECRET],
-                API_URLS[user_input[CONF_API_URL]],
-            )
-            try:
-                await api_client.async_get_token()
-            except InvalidAppIdOrSecretException:
-                errors["base"] = "invalid_auth"
-            except ConnectFailedException, RequestFailedException:
-                errors["base"] = "cannot_connect"
-            except ImouException as exception:
-                _LOGGER.debug("Imou error during config flow: %s", exception)
-                errors["base"] = "unknown"
-            else:
+            if not (errors := await self._validate_input(user_input)):
                 return self.async_create_entry(
                     title="Imou",
                     data={
@@ -79,3 +101,38 @@ class ImouConfigFlow(ConfigFlow, domain=DOMAIN):
             ),
             errors=errors,
         )
+
+    async def async_step_reauth(
+        self, entry_data: Mapping[str, Any]
+    ) -> ConfigFlowResult:
+        """Perform reauthentication upon an API authentication error."""
+        return await self.async_step_reauth_confirm()
+
+    async def async_step_reauth_confirm(
+        self, user_input: dict[str, Any] | None = None
+    ) -> ConfigFlowResult:
+        """Confirm reauthentication with a new App secret."""
+        errors: dict[str, str] = {}
+        reauth_entry = self._get_reauth_entry()
+        if user_input is not None:
+            if not (
+                errors := await self._validate_input(
+                    {
+                        CONF_APP_ID: reauth_entry.data[CONF_APP_ID],
+                        CONF_APP_SECRET: user_input[CONF_APP_SECRET],
+                        CONF_API_URL: reauth_entry.data[CONF_API_URL],
+                    }
+                )
+            ):
+                await self.async_set_unique_id(reauth_entry.data[CONF_APP_ID])
+                self._abort_if_unique_id_mismatch()
+                return self.async_update_reload_and_abort(
+                    reauth_entry,
+                    data_updates={CONF_APP_SECRET: user_input[CONF_APP_SECRET]},
+                )
+        return self.async_show_form(
+            step_id="reauth_confirm",
+            data_schema=REAUTH_SCHEMA,
+            description_placeholders={"app_id": reauth_entry.data[CONF_APP_ID]},
+            errors=errors,
+        )
diff --git a/homeassistant/components/imou/quality_scale.yaml b/homeassistant/components/imou/quality_scale.yaml
index 21e8faea2146..a9c86bee01c3 100644
--- a/homeassistant/components/imou/quality_scale.yaml
+++ b/homeassistant/components/imou/quality_scale.yaml
@@ -40,7 +40,7 @@ rules:
   integration-owner: done
   log-when-unavailable: done
   parallel-updates: done
-  reauthentication-flow: todo
+  reauthentication-flow: done
   test-coverage: todo
 
   # Gold
diff --git a/homeassistant/components/imou/strings.json b/homeassistant/components/imou/strings.json
index 889a603f56b1..4c45bc362cd2 100644
--- a/homeassistant/components/imou/strings.json
+++ b/homeassistant/components/imou/strings.json
@@ -2,7 +2,9 @@
   "config": {
     "abort": {
       "already_configured": "[%key:common::config_flow::abort::already_configured_account%]",
-      "already_in_progress": "[%key:common::config_flow::abort::already_in_progress%]"
+      "already_in_progress": "[%key:common::config_flow::abort::already_in_progress%]",
+      "reauth_successful": "[%key:common::config_flow::abort::reauth_successful%]",
+      "unique_id_mismatch": "The App ID does not match the previously configured account."
     },
     "error": {
       "cannot_connect": "[%key:common::config_flow::error::cannot_connect%]",
@@ -10,6 +12,16 @@
       "unknown": "[%key:common::config_flow::error::unknown%]"
     },
     "step": {
+      "reauth_confirm": {
+        "data": {
+          "app_secret": "[%key:component::imou::config::step::user::data::app_secret%]"
+        },
+        "data_description": {
+          "app_secret": "[%key:component::imou::config::step::user::data_description::app_secret%]"
+        },
+        "description": "Enter a new App secret for {app_id}.",
+        "title": "[%key:common::config_flow::title::reauth%]"
+      },
       "user": {
         "data": {
           "api_url": "Server region",
diff --git a/tests/components/imou/test_config_flow.py b/tests/components/imou/test_config_flow.py
index d6e8eaad8917..700fe9df47fd 100644
--- a/tests/components/imou/test_config_flow.py
+++ b/tests/components/imou/test_config_flow.py
@@ -31,6 +31,8 @@ DHCP_DISCOVERY = DhcpServiceInfo(
     macaddress="1c4d895f7a29",
 )
 
+NEW_APP_SECRET = "new_app_secret"
+
 
 async def test_user_flow_success(
     hass: HomeAssistant,
@@ -262,3 +264,92 @@ async def test_dhcp_discovery_invalid_auth(
     assert result["data"] == USER_INPUT
     assert result["result"].unique_id == USER_INPUT[CONF_APP_ID]
     assert len(mock_setup_entry.mock_calls) == 1
+
+
+@pytest.mark.usefixtures("mock_setup_entry")
+async def test_reauth_flow_success(
+    hass: HomeAssistant,
+    mock_imou_openapi_client: AsyncMock,
+    mock_config_entry: MockConfigEntry,
+) -> None:
+    """Reauth updates the App secret and reloads the entry."""
+    mock_config_entry.add_to_hass(hass)
+
+    result = await mock_config_entry.start_reauth_flow(hass)
+
+    assert result["type"] is FlowResultType.FORM
+    assert result["step_id"] == "reauth_confirm"
+
+    result = await hass.config_entries.flow.async_configure(
+        result["flow_id"],
+        user_input={CONF_APP_SECRET: NEW_APP_SECRET},
+    )
+
+    assert result["type"] is FlowResultType.ABORT
+    assert result["reason"] == "reauth_successful"
+    assert mock_config_entry.data[CONF_APP_SECRET] == NEW_APP_SECRET
+    mock_imou_openapi_client.async_close.assert_awaited_once()
+
+
+@pytest.mark.parametrize(
+    ("side_effect", "expected_error"),
+    [
+        (ConnectFailedException("fail"), "cannot_connect"),
+        (RequestFailedException("fail"), "cannot_connect"),
+        (InvalidAppIdOrSecretException("fail"), "invalid_auth"),
+        (ImouException("fail"), "unknown"),
+    ],
+)
+@pytest.mark.usefixtures("mock_setup_entry")
+async def test_reauth_flow_exception_then_recover(
+    hass: HomeAssistant,
+    mock_imou_openapi_client: AsyncMock,
+    mock_config_entry: MockConfigEntry,
+    side_effect: Exception,
+    expected_error: str,
+) -> None:
+    """Errors map to stable keys; clearing the failure allows completing reauth."""
+    mock_config_entry.add_to_hass(hass)
+    mock_imou_openapi_client.async_get_token.side_effect = side_effect
+
+    result = await mock_config_entry.start_reauth_flow(hass)
+    result = await hass.config_entries.flow.async_configure(
+        result["flow_id"],
+        user_input={CONF_APP_SECRET: NEW_APP_SECRET},
+    )
+
+    assert result["type"] is FlowResultType.FORM
+    assert result["step_id"] == "reauth_confirm"
+    assert result["errors"]["base"] == expected_error
+
+    mock_imou_openapi_client.async_get_token.reset_mock(side_effect=True)
+
+    result = await hass.config_entries.flow.async_configure(
+        result["flow_id"],
+        user_input={CONF_APP_SECRET: NEW_APP_SECRET},
+    )
+
+    assert result["type"] is FlowResultType.ABORT
+    assert result["reason"] == "reauth_successful"
+    assert mock_config_entry.data[CONF_APP_SECRET] == NEW_APP_SECRET
+    assert mock_imou_openapi_client.async_close.await_count == 2
+
+
+@pytest.mark.usefixtures("mock_setup_entry")
+async def test_reauth_unique_id_mismatch(
+    hass: HomeAssistant,
+    mock_imou_openapi_client: AsyncMock,
+    mock_config_entry: MockConfigEntry,
+) -> None:
+    """Reauth aborts when the unique ID does not match the existing entry."""
+    mock_config_entry.add_to_hass(hass)
+    hass.config_entries.async_update_entry(mock_config_entry, unique_id="other-app-id")
+
+    result = await mock_config_entry.start_reauth_flow(hass)
+    result = await hass.config_entries.flow.async_configure(
+        result["flow_id"],
+        user_input={CONF_APP_SECRET: NEW_APP_SECRET},
+    )
+
+    assert result["type"] is FlowResultType.ABORT
+    assert result["reason"] == "unique_id_mismatch"