diff --git a/homeassistant/components/google_assistant/trait.py b/homeassistant/components/google_assistant/trait.py
index 28c939ec261..497234df4ee 100644
--- a/homeassistant/components/google_assistant/trait.py
+++ b/homeassistant/components/google_assistant/trait.py
@@ -2309,8 +2309,8 @@ class SensorStateTrait(_Trait):
 
     sensor_types = {
         sensor.SensorDeviceClass.AQI: ("AirQuality", "AQI"),
-        sensor.SensorDeviceClass.CO: ("CarbonDioxideLevel", "PARTS_PER_MILLION"),
-        sensor.SensorDeviceClass.CO2: ("CarbonMonoxideLevel", "PARTS_PER_MILLION"),
+        sensor.SensorDeviceClass.CO: ("CarbonMonoxideLevel", "PARTS_PER_MILLION"),
+        sensor.SensorDeviceClass.CO2: ("CarbonDioxideLevel", "PARTS_PER_MILLION"),
         sensor.SensorDeviceClass.PM25: ("PM2.5", "MICROGRAMS_PER_CUBIC_METER"),
         sensor.SensorDeviceClass.PM10: ("PM10", "MICROGRAMS_PER_CUBIC_METER"),
         sensor.SensorDeviceClass.VOLATILE_ORGANIC_COMPOUNDS: (
diff --git a/tests/components/google_assistant/test_trait.py b/tests/components/google_assistant/test_trait.py
index 83fcaa59b19..8229d857173 100644
--- a/tests/components/google_assistant/test_trait.py
+++ b/tests/components/google_assistant/test_trait.py
@@ -3046,8 +3046,8 @@ async def test_sensorstate(hass):
     """Test SensorState trait support for sensor domain."""
     sensor_types = {
         sensor.SensorDeviceClass.AQI: ("AirQuality", "AQI"),
-        sensor.SensorDeviceClass.CO: ("CarbonDioxideLevel", "PARTS_PER_MILLION"),
-        sensor.SensorDeviceClass.CO2: ("CarbonMonoxideLevel", "PARTS_PER_MILLION"),
+        sensor.SensorDeviceClass.CO: ("CarbonMonoxideLevel", "PARTS_PER_MILLION"),
+        sensor.SensorDeviceClass.CO2: ("CarbonDioxideLevel", "PARTS_PER_MILLION"),
         sensor.SensorDeviceClass.PM25: ("PM2.5", "MICROGRAMS_PER_CUBIC_METER"),
         sensor.SensorDeviceClass.PM10: ("PM10", "MICROGRAMS_PER_CUBIC_METER"),
         sensor.SensorDeviceClass.VOLATILE_ORGANIC_COMPOUNDS: (