diff --git a/esphome/components/sensor/__init__.py b/esphome/components/sensor/__init__.py
index d449568f0e..9c0b0bedd1 100644
--- a/esphome/components/sensor/__init__.py
+++ b/esphome/components/sensor/__init__.py
@@ -33,6 +33,8 @@ from esphome.const import (
     ICON_EMPTY,
     DEVICE_CLASS_EMPTY,
     DEVICE_CLASS_BATTERY,
+    DEVICE_CLASS_CARBON_MONOXIDE,
+    DEVICE_CLASS_CARBON_DIOXIDE,
     DEVICE_CLASS_CURRENT,
     DEVICE_CLASS_ENERGY,
     DEVICE_CLASS_HUMIDITY,
@@ -52,16 +54,18 @@ CODEOWNERS = ["@esphome/core"]
 DEVICE_CLASSES = [
     DEVICE_CLASS_EMPTY,
     DEVICE_CLASS_BATTERY,
+    DEVICE_CLASS_CARBON_MONOXIDE,
+    DEVICE_CLASS_CARBON_DIOXIDE,
     DEVICE_CLASS_CURRENT,
     DEVICE_CLASS_ENERGY,
     DEVICE_CLASS_HUMIDITY,
     DEVICE_CLASS_ILLUMINANCE,
     DEVICE_CLASS_SIGNAL_STRENGTH,
     DEVICE_CLASS_TEMPERATURE,
+    DEVICE_CLASS_TIMESTAMP,
     DEVICE_CLASS_POWER,
     DEVICE_CLASS_POWER_FACTOR,
     DEVICE_CLASS_PRESSURE,
-    DEVICE_CLASS_TIMESTAMP,
     DEVICE_CLASS_VOLTAGE,
 ]
 
diff --git a/esphome/const.py b/esphome/const.py
index e93d2b7d25..d44e995fc8 100644
--- a/esphome/const.py
+++ b/esphome/const.py
@@ -746,6 +746,8 @@ DEVICE_CLASS_EMPTY = ""
 DEVICE_CLASS_BATTERY = "battery"
 DEVICE_CLASS_POWER = "power"
 # device classes of sensor component
+DEVICE_CLASS_CARBON_MONOXIDE = "carbon_monoxide"
+DEVICE_CLASS_CARBON_DIOXIDE = "carbon_dioxide"
 DEVICE_CLASS_CURRENT = "current"
 DEVICE_CLASS_ENERGY = "energy"
 DEVICE_CLASS_HUMIDITY = "humidity"