diff --git a/homeassistant/components/vizio/config_flow.py b/homeassistant/components/vizio/config_flow.py
index f3b7720a33e..b6d6d9bfb05 100644
--- a/homeassistant/components/vizio/config_flow.py
+++ b/homeassistant/components/vizio/config_flow.py
@@ -348,9 +348,11 @@ class VizioConfigFlow(config_entries.ConfigFlow, domain=DOMAIN):
         """Handle zeroconf discovery."""
         assert self.hass
 
-        discovery_info[
-            CONF_HOST
-        ] = f"{discovery_info[CONF_HOST]}:{discovery_info[CONF_PORT]}"
+        # If host already has port, no need to add it again
+        if ":" not in discovery_info[CONF_HOST]:
+            discovery_info[
+                CONF_HOST
+            ] = f"{discovery_info[CONF_HOST]}:{discovery_info[CONF_PORT]}"
 
         # Set default name to discovered device name by stripping zeroconf service
         # (`type`) from `name`
diff --git a/tests/components/vizio/test_config_flow.py b/tests/components/vizio/test_config_flow.py
index 5cbc2fa5564..32469fabd05 100644
--- a/tests/components/vizio/test_config_flow.py
+++ b/tests/components/vizio/test_config_flow.py
@@ -27,6 +27,7 @@ from homeassistant.const import (
     CONF_HOST,
     CONF_NAME,
     CONF_PIN,
+    CONF_PORT,
 )
 from homeassistant.helpers.typing import HomeAssistantType
 
@@ -777,6 +778,35 @@ async def test_zeroconf_flow_already_configured(
     assert result["reason"] == "already_configured"
 
 
+async def test_zeroconf_flow_with_port_in_host(
+    hass: HomeAssistantType,
+    vizio_connect: pytest.fixture,
+    vizio_bypass_setup: pytest.fixture,
+    vizio_guess_device_type: pytest.fixture,
+) -> None:
+    """Test entity is already configured during zeroconf setup when port is in host."""
+    entry = MockConfigEntry(
+        domain=DOMAIN,
+        data=MOCK_SPEAKER_CONFIG,
+        options={CONF_VOLUME_STEP: VOLUME_STEP},
+        unique_id=UNIQUE_ID,
+    )
+    entry.add_to_hass(hass)
+
+    # Try rediscovering same device, this time with port already in host
+    discovery_info = MOCK_ZEROCONF_SERVICE_INFO.copy()
+    discovery_info[
+        CONF_HOST
+    ] = f"{discovery_info[CONF_HOST]}:{discovery_info[CONF_PORT]}"
+    result = await hass.config_entries.flow.async_init(
+        DOMAIN, context={"source": SOURCE_ZEROCONF}, data=discovery_info
+    )
+
+    # Flow should abort because device is already setup
+    assert result["type"] == data_entry_flow.RESULT_TYPE_ABORT
+    assert result["reason"] == "already_configured"
+
+
 async def test_zeroconf_dupe_fail(
     hass: HomeAssistantType,
     vizio_connect: pytest.fixture,