diff --git a/homeassistant/components/onvif/config_flow.py b/homeassistant/components/onvif/config_flow.py
index 181b3321c53..68a4ce52511 100644
--- a/homeassistant/components/onvif/config_flow.py
+++ b/homeassistant/components/onvif/config_flow.py
@@ -316,6 +316,15 @@ class OnvifFlowHandler(config_entries.ConfigFlow, domain=DOMAIN):
             # Verify there is an H264 profile
             media_service = device.create_media_service()
             profiles = await media_service.GetProfiles()
+        except AttributeError:  # Likely an empty document or 404 from the wrong port
+            LOGGER.debug(
+                "%s: No ONVIF service found at %s:%s",
+                self.onvif_config[CONF_NAME],
+                self.onvif_config[CONF_HOST],
+                self.onvif_config[CONF_PORT],
+                exc_info=True,
+            )
+            return {CONF_PORT: "no_onvif_service"}, {}
         except Fault as err:
             stringified_error = stringify_onvif_error(err)
             description_placeholders = {"error": stringified_error}
diff --git a/homeassistant/components/onvif/strings.json b/homeassistant/components/onvif/strings.json
index 07f2e6fb7ac..55413e4bf6c 100644
--- a/homeassistant/components/onvif/strings.json
+++ b/homeassistant/components/onvif/strings.json
@@ -11,6 +11,7 @@
     "error": {
       "onvif_error": "Error setting up ONVIF device: {error}. Check logs for more information.",
       "auth_failed": "Could not authenticate: {error}",
+      "no_onvif_service": "No ONVIF service found. Check that the port number is correct.",
       "cannot_connect": "[%key:common::config_flow::error::cannot_connect%]"
     },
     "step": {
diff --git a/tests/components/onvif/__init__.py b/tests/components/onvif/__init__.py
index 1dfcc85cd28..18de9839e1b 100644
--- a/tests/components/onvif/__init__.py
+++ b/tests/components/onvif/__init__.py
@@ -45,12 +45,14 @@ def setup_mock_onvif_camera(
     update_xaddrs_fail=False,
     no_profiles=False,
     auth_failure=False,
+    wrong_port=False,
 ):
     """Prepare mock onvif.ONVIFCamera."""
     devicemgmt = MagicMock()
 
     device_info = MagicMock()
     device_info.SerialNumber = SERIAL_NUMBER if with_serial else None
+
     devicemgmt.GetDeviceInformation = AsyncMock(return_value=device_info)
 
     interface = MagicMock()
@@ -82,7 +84,9 @@ def setup_mock_onvif_camera(
     else:
         media_service.GetProfiles = AsyncMock(return_value=[profile1, profile2])
 
-    if auth_failure:
+    if wrong_port:
+        mock_onvif_camera.update_xaddrs = AsyncMock(side_effect=AttributeError)
+    elif auth_failure:
         mock_onvif_camera.update_xaddrs = AsyncMock(
             side_effect=Fault(
                 "not authorized", subcodes=[MagicMock(text="NotAuthorized")]
diff --git a/tests/components/onvif/test_config_flow.py b/tests/components/onvif/test_config_flow.py
index 805b5d85db8..21ef1cf3fc2 100644
--- a/tests/components/onvif/test_config_flow.py
+++ b/tests/components/onvif/test_config_flow.py
@@ -829,3 +829,82 @@ async def test_flow_manual_entry_updates_existing_user_password(
         assert entry.data[config_flow.CONF_USERNAME] == USERNAME
         assert entry.data[config_flow.CONF_PASSWORD] == "new_password"
         assert len(mock_setup_entry.mock_calls) == 1
+
+
+async def test_flow_manual_entry_wrong_port(hass: HomeAssistant) -> None:
+    """Test that we get a useful error with the wrong port."""
+    result = await hass.config_entries.flow.async_init(
+        config_flow.DOMAIN, context={"source": config_entries.SOURCE_USER}
+    )
+
+    assert result["type"] == data_entry_flow.FlowResultType.FORM
+    assert result["step_id"] == "user"
+
+    with patch(
+        "homeassistant.components.onvif.config_flow.get_device"
+    ) as mock_onvif_camera, patch(
+        "homeassistant.components.onvif.config_flow.wsdiscovery"
+    ) as mock_discovery, patch(
+        "homeassistant.components.onvif.ONVIFDevice"
+    ) as mock_device:
+        setup_mock_onvif_camera(mock_onvif_camera, wrong_port=True)
+        # no discovery
+        mock_discovery.return_value = []
+        setup_mock_device(mock_device)
+
+        result = await hass.config_entries.flow.async_configure(
+            result["flow_id"],
+            user_input={"auto": False},
+        )
+
+        assert result["type"] == data_entry_flow.FlowResultType.FORM
+        assert result["step_id"] == "configure"
+
+        with patch(
+            "homeassistant.components.onvif.async_setup_entry", return_value=True
+        ) as mock_setup_entry:
+            result = await hass.config_entries.flow.async_configure(
+                result["flow_id"],
+                user_input={
+                    config_flow.CONF_NAME: NAME,
+                    config_flow.CONF_HOST: HOST,
+                    config_flow.CONF_PORT: PORT,
+                    config_flow.CONF_USERNAME: USERNAME,
+                    config_flow.CONF_PASSWORD: PASSWORD,
+                },
+            )
+
+            await hass.async_block_till_done()
+            assert len(mock_setup_entry.mock_calls) == 0
+
+        assert result["type"] == data_entry_flow.FlowResultType.FORM
+        assert result["step_id"] == "configure"
+        assert result["errors"] == {"port": "no_onvif_service"}
+        assert result["description_placeholders"] == {}
+        setup_mock_onvif_camera(mock_onvif_camera, two_profiles=True)
+
+        with patch(
+            "homeassistant.components.onvif.async_setup_entry", return_value=True
+        ) as mock_setup_entry:
+            result = await hass.config_entries.flow.async_configure(
+                result["flow_id"],
+                user_input={
+                    config_flow.CONF_NAME: NAME,
+                    config_flow.CONF_HOST: HOST,
+                    config_flow.CONF_PORT: PORT,
+                    config_flow.CONF_USERNAME: USERNAME,
+                    config_flow.CONF_PASSWORD: PASSWORD,
+                },
+            )
+
+            await hass.async_block_till_done()
+            assert len(mock_setup_entry.mock_calls) == 1
+
+        assert result["title"] == f"{NAME} - {MAC}"
+        assert result["data"] == {
+            config_flow.CONF_NAME: NAME,
+            config_flow.CONF_HOST: HOST,
+            config_flow.CONF_PORT: PORT,
+            config_flow.CONF_USERNAME: USERNAME,
+            config_flow.CONF_PASSWORD: PASSWORD,
+        }