diff --git a/homeassistant/components/onewire/const.py b/homeassistant/components/onewire/const.py
index 23a686767b0..83ffa12706c 100644
--- a/homeassistant/components/onewire/const.py
+++ b/homeassistant/components/onewire/const.py
@@ -13,6 +13,8 @@ DEFAULT_SYSBUS_MOUNT_DIR = "/sys/bus/w1/devices/"
 
 DOMAIN = "onewire"
 
+PRESSURE_CBAR = "cbar"
+
 SUPPORTED_PLATFORMS = [
     SENSOR_DOMAIN,
 ]
diff --git a/homeassistant/components/onewire/sensor.py b/homeassistant/components/onewire/sensor.py
index d6e8ef50f46..3b7eeb50c29 100644
--- a/homeassistant/components/onewire/sensor.py
+++ b/homeassistant/components/onewire/sensor.py
@@ -14,6 +14,7 @@ from homeassistant.const import (
     ELECTRICAL_CURRENT_AMPERE,
     LIGHT_LUX,
     PERCENTAGE,
+    PRESSURE_MBAR,
     TEMP_CELSIUS,
     VOLT,
 )
@@ -28,6 +29,7 @@ from .const import (
     CONF_TYPE_SYSBUS,
     DEFAULT_OWSERVER_PORT,
     DEFAULT_SYSBUS_MOUNT_DIR,
+    PRESSURE_CBAR,
 )
 
 _LOGGER = logging.getLogger(__name__)
@@ -86,16 +88,16 @@ SENSOR_TYPES = {
     "humidity_hih5030": ["humidity", PERCENTAGE],
     "humidity_htm1735": ["humidity", PERCENTAGE],
     "humidity_raw": ["humidity", PERCENTAGE],
-    "pressure": ["pressure", "mb"],
+    "pressure": ["pressure", PRESSURE_MBAR],
     "illuminance": ["illuminance", LIGHT_LUX],
     "wetness_0": ["wetness", PERCENTAGE],
     "wetness_1": ["wetness", PERCENTAGE],
     "wetness_2": ["wetness", PERCENTAGE],
     "wetness_3": ["wetness", PERCENTAGE],
-    "moisture_0": ["moisture", "cb"],
-    "moisture_1": ["moisture", "cb"],
-    "moisture_2": ["moisture", "cb"],
-    "moisture_3": ["moisture", "cb"],
+    "moisture_0": ["moisture", PRESSURE_CBAR],
+    "moisture_1": ["moisture", PRESSURE_CBAR],
+    "moisture_2": ["moisture", PRESSURE_CBAR],
+    "moisture_3": ["moisture", PRESSURE_CBAR],
     "counter_a": ["counter", "count"],
     "counter_b": ["counter", "count"],
     "HobbyBoard": ["none", "none"],
diff --git a/tests/components/onewire/test_entity_owserver.py b/tests/components/onewire/test_entity_owserver.py
index 290c744ab94..95b0137f7eb 100644
--- a/tests/components/onewire/test_entity_owserver.py
+++ b/tests/components/onewire/test_entity_owserver.py
@@ -4,7 +4,11 @@ from unittest.mock import patch
 from pyownet.protocol import Error as ProtocolError
 import pytest
 
-from homeassistant.components.onewire.const import DEFAULT_OWSERVER_PORT, DOMAIN
+from homeassistant.components.onewire.const import (
+    DEFAULT_OWSERVER_PORT,
+    DOMAIN,
+    PRESSURE_CBAR,
+)
 from homeassistant.components.sensor import DOMAIN as SENSOR_DOMAIN
 from homeassistant.const import PERCENTAGE, TEMP_CELSIUS
 from homeassistant.setup import async_setup_component
@@ -153,14 +157,14 @@ MOCK_DEVICE_SENSORS = {
                 "unique_id": "/EF.111111111112/moisture/sensor.2",
                 "injected_value": b"    43.123",
                 "result": "43.1",
-                "unit": "cb",
+                "unit": PRESSURE_CBAR,
             },
             {
                 "entity_id": "sensor.ef_111111111112_moisture_3",
                 "unique_id": "/EF.111111111112/moisture/sensor.3",
                 "injected_value": b"    44.123",
                 "result": "44.1",
-                "unit": "cb",
+                "unit": PRESSURE_CBAR,
             },
         ],
     },