diff --git a/homeassistant/components/persistent_notification/__init__.py b/homeassistant/components/persistent_notification/__init__.py
index 960d0a5ca598f3..581720c2730346 100644
--- a/homeassistant/components/persistent_notification/__init__.py
+++ b/homeassistant/components/persistent_notification/__init__.py
@@ -140,6 +140,20 @@ def async_dismiss(hass: HomeAssistant, notification_id: str) -> None:
     )
 
 
+@callback
+def async_dismiss_all(hass: HomeAssistant) -> None:
+    """Remove all notifications."""
+    notifications = _async_get_or_create_notifications(hass)
+    notifications_copy = notifications.copy()
+    notifications.clear()
+    async_dispatcher_send(
+        hass,
+        SIGNAL_PERSISTENT_NOTIFICATIONS_UPDATED,
+        UpdateType.REMOVED,
+        notifications_copy,
+    )
+
+
 async def async_setup(hass: HomeAssistant, config: ConfigType) -> bool:
     """Set up the persistent notification component."""
 
@@ -158,6 +172,11 @@ def dismiss_service(call: ServiceCall) -> None:
         """Handle the dismiss notification service call."""
         async_dismiss(hass, call.data[ATTR_NOTIFICATION_ID])
 
+    @callback
+    def dismiss_all_service(call: ServiceCall) -> None:
+        """Handle the dismiss all notification service call."""
+        async_dismiss_all(hass)
+
     hass.services.async_register(
         DOMAIN,
         "create",
@@ -175,6 +194,8 @@ def dismiss_service(call: ServiceCall) -> None:
         DOMAIN, "dismiss", dismiss_service, SCHEMA_SERVICE_NOTIFICATION
     )
 
+    hass.services.async_register(DOMAIN, "dismiss_all", dismiss_all_service, None)
+
     websocket_api.async_register_command(hass, websocket_get_notifications)
     websocket_api.async_register_command(hass, websocket_subscribe_notifications)
 
diff --git a/homeassistant/components/persistent_notification/services.yaml b/homeassistant/components/persistent_notification/services.yaml
index 60dbf5c864acc2..5ebd7e34409ad1 100644
--- a/homeassistant/components/persistent_notification/services.yaml
+++ b/homeassistant/components/persistent_notification/services.yaml
@@ -33,3 +33,7 @@ dismiss:
       example: 1234
       selector:
         text:
+
+dismiss_all:
+  name: Dismiss All
+  description: Remove all notifications.
diff --git a/tests/components/persistent_notification/test_init.py b/tests/components/persistent_notification/test_init.py
index 71a0fcae917483..921f4b120450a0 100644
--- a/tests/components/persistent_notification/test_init.py
+++ b/tests/components/persistent_notification/test_init.py
@@ -54,11 +54,31 @@ async def test_dismiss_notification(hass: HomeAssistant) -> None:
     pn.async_create(hass, "test", notification_id="Beer 2")
 
     assert len(notifications) == 1
+    pn.async_dismiss(hass, notification_id="Does Not Exist")
+
+    assert len(notifications) == 1
+
     pn.async_dismiss(hass, notification_id="Beer 2")
 
     assert len(notifications) == 0
 
 
+async def test_dismiss_all_notifications(hass: HomeAssistant) -> None:
+    """Ensure removal of all notifications."""
+    notifications = pn._async_get_or_create_notifications(hass)
+    assert len(notifications) == 0
+
+    pn.async_create(hass, "test", notification_id="Beer 2")
+    pn.async_create(hass, "test", notification_id="Beer 3")
+    pn.async_create(hass, "test", notification_id="Beer 4")
+    pn.async_create(hass, "test", notification_id="Beer 5")
+
+    assert len(notifications) == 4
+    pn.async_dismiss_all(hass)
+
+    assert len(notifications) == 0
+
+
 async def test_ws_get_notifications(
     hass: HomeAssistant, hass_ws_client: WebSocketGenerator
 ) -> None:
@@ -169,3 +189,34 @@ async def test_manual_notification_id_round_trip(hass: HomeAssistant) -> None:
     )
 
     assert len(notifications) == 0
+
+
+async def test_manual_dismiss_all(hass: HomeAssistant) -> None:
+    """Test the dismiss all service."""
+    notifications = pn._async_get_or_create_notifications(hass)
+    assert len(notifications) == 0
+
+    await hass.services.async_call(
+        pn.DOMAIN,
+        "create",
+        {"notification_id": "Beer 1", "message": "test"},
+        blocking=True,
+    )
+
+    await hass.services.async_call(
+        pn.DOMAIN,
+        "create",
+        {"notification_id": "Beer 2", "message": "test 2"},
+        blocking=True,
+    )
+
+    assert len(notifications) == 2
+
+    await hass.services.async_call(
+        pn.DOMAIN,
+        "dismiss_all",
+        None,
+        blocking=True,
+    )
+
+    assert len(notifications) == 0