diff --git a/homeassistant/components/blink/sensor.py b/homeassistant/components/blink/sensor.py
index 35cc2d0d5a5d..3c3adf6d990e 100644
--- a/homeassistant/components/blink/sensor.py
+++ b/homeassistant/components/blink/sensor.py
@@ -4,6 +4,7 @@ import logging
 from homeassistant.const import (
     DEVICE_CLASS_SIGNAL_STRENGTH,
     DEVICE_CLASS_TEMPERATURE,
+    SIGNAL_STRENGTH_DECIBELS_MILLIWATT,
     TEMP_FAHRENHEIT,
 )
 from homeassistant.helpers.entity import Entity
@@ -14,7 +15,11 @@ _LOGGER = logging.getLogger(__name__)
 
 SENSORS = {
     TYPE_TEMPERATURE: ["Temperature", TEMP_FAHRENHEIT, DEVICE_CLASS_TEMPERATURE],
-    TYPE_WIFI_STRENGTH: ["Wifi Signal", "dBm", DEVICE_CLASS_SIGNAL_STRENGTH],
+    TYPE_WIFI_STRENGTH: [
+        "Wifi Signal",
+        SIGNAL_STRENGTH_DECIBELS_MILLIWATT,
+        DEVICE_CLASS_SIGNAL_STRENGTH,
+    ],
 }
 
 
diff --git a/homeassistant/components/canary/sensor.py b/homeassistant/components/canary/sensor.py
index 6ec9f3a87ff0..99dcdf48fced 100644
--- a/homeassistant/components/canary/sensor.py
+++ b/homeassistant/components/canary/sensor.py
@@ -10,6 +10,7 @@ from homeassistant.const import (
     DEVICE_CLASS_SIGNAL_STRENGTH,
     DEVICE_CLASS_TEMPERATURE,
     PERCENTAGE,
+    SIGNAL_STRENGTH_DECIBELS_MILLIWATT,
     TEMP_CELSIUS,
 )
 from homeassistant.helpers.entity import Entity
@@ -35,7 +36,13 @@ SENSOR_TYPES = [
     ["temperature", TEMP_CELSIUS, None, DEVICE_CLASS_TEMPERATURE, [CANARY_PRO]],
     ["humidity", PERCENTAGE, None, DEVICE_CLASS_HUMIDITY, [CANARY_PRO]],
     ["air_quality", None, "mdi:weather-windy", None, [CANARY_PRO]],
-    ["wifi", "dBm", None, DEVICE_CLASS_SIGNAL_STRENGTH, [CANARY_FLEX]],
+    [
+        "wifi",
+        SIGNAL_STRENGTH_DECIBELS_MILLIWATT,
+        None,
+        DEVICE_CLASS_SIGNAL_STRENGTH,
+        [CANARY_FLEX],
+    ],
     ["battery", PERCENTAGE, None, DEVICE_CLASS_BATTERY, [CANARY_FLEX]],
 ]
 
diff --git a/homeassistant/components/netgear_lte/sensor_types.py b/homeassistant/components/netgear_lte/sensor_types.py
index e354c84e715d..644fe35c8c3e 100644
--- a/homeassistant/components/netgear_lte/sensor_types.py
+++ b/homeassistant/components/netgear_lte/sensor_types.py
@@ -1,7 +1,11 @@
 """Define possible sensor types."""
 
 from homeassistant.components.binary_sensor import DEVICE_CLASS_CONNECTIVITY
-from homeassistant.const import DATA_MEBIBYTES, PERCENTAGE
+from homeassistant.const import (
+    DATA_MEBIBYTES,
+    PERCENTAGE,
+    SIGNAL_STRENGTH_DECIBELS_MILLIWATT,
+)
 
 SENSOR_SMS = "sms"
 SENSOR_SMS_TOTAL = "sms_total"
@@ -12,8 +16,8 @@ SENSOR_UNITS = {
     SENSOR_SMS_TOTAL: "messages",
     SENSOR_USAGE: DATA_MEBIBYTES,
     "radio_quality": PERCENTAGE,
-    "rx_level": "dBm",
-    "tx_level": "dBm",
+    "rx_level": SIGNAL_STRENGTH_DECIBELS_MILLIWATT,
+    "tx_level": SIGNAL_STRENGTH_DECIBELS_MILLIWATT,
     "upstream": None,
     "connection_text": None,
     "connection_type": None,
diff --git a/homeassistant/components/rfxtrx/__init__.py b/homeassistant/components/rfxtrx/__init__.py
index c12a6380f202..ccdf79772aa3 100644
--- a/homeassistant/components/rfxtrx/__init__.py
+++ b/homeassistant/components/rfxtrx/__init__.py
@@ -27,6 +27,7 @@ from homeassistant.const import (
     PERCENTAGE,
     POWER_WATT,
     PRESSURE_HPA,
+    SIGNAL_STRENGTH_DECIBELS_MILLIWATT,
     SPEED_METERS_PER_SECOND,
     TEMP_CELSIUS,
     TIME_HOURS,
@@ -86,7 +87,7 @@ DATA_TYPES = OrderedDict(
         ("Voltage", VOLT),
         ("Current", ELECTRICAL_CURRENT_AMPERE),
         ("Battery numeric", PERCENTAGE),
-        ("Rssi numeric", "dBm"),
+        ("Rssi numeric", SIGNAL_STRENGTH_DECIBELS_MILLIWATT),
     ]
 )
 
diff --git a/homeassistant/components/ring/sensor.py b/homeassistant/components/ring/sensor.py
index 24a5cd3b6fb7..f59c3b2e61d2 100644
--- a/homeassistant/components/ring/sensor.py
+++ b/homeassistant/components/ring/sensor.py
@@ -1,7 +1,7 @@
 """This component provides HA sensor support for Ring Door Bell/Chimes."""
 import logging
 
-from homeassistant.const import PERCENTAGE
+from homeassistant.const import PERCENTAGE, SIGNAL_STRENGTH_DECIBELS_MILLIWATT
 from homeassistant.core import callback
 from homeassistant.helpers.entity import Entity
 from homeassistant.helpers.icon import icon_for_battery_level
@@ -256,7 +256,7 @@ SENSOR_TYPES = {
     "wifi_signal_strength": [
         "WiFi Signal Strength",
         ["chimes", "doorbots", "authorized_doorbots", "stickup_cams"],
-        "dBm",
+        SIGNAL_STRENGTH_DECIBELS_MILLIWATT,
         "wifi",
         None,
         "signal_strength",
diff --git a/homeassistant/components/sms/sensor.py b/homeassistant/components/sms/sensor.py
index 64d2bf9bd987..eaad395eaa69 100644
--- a/homeassistant/components/sms/sensor.py
+++ b/homeassistant/components/sms/sensor.py
@@ -3,7 +3,7 @@ import logging
 
 import gammu  # pylint: disable=import-error, no-member
 
-from homeassistant.const import DEVICE_CLASS_SIGNAL_STRENGTH
+from homeassistant.const import DEVICE_CLASS_SIGNAL_STRENGTH, SIGNAL_STRENGTH_DECIBELS
 from homeassistant.helpers.entity import Entity
 
 from .const import DOMAIN, SMS_GATEWAY
@@ -50,7 +50,7 @@ class GSMSignalSensor(Entity):
     @property
     def unit_of_measurement(self):
         """Return the unit the value is expressed in."""
-        return "dB"
+        return SIGNAL_STRENGTH_DECIBELS
 
     @property
     def device_class(self):
diff --git a/homeassistant/components/wirelesstag/__init__.py b/homeassistant/components/wirelesstag/__init__.py
index 702479c4112c..ba45844597b7 100644
--- a/homeassistant/components/wirelesstag/__init__.py
+++ b/homeassistant/components/wirelesstag/__init__.py
@@ -12,6 +12,7 @@ from homeassistant.const import (
     CONF_PASSWORD,
     CONF_USERNAME,
     PERCENTAGE,
+    SIGNAL_STRENGTH_DECIBELS_MILLIWATT,
     VOLT,
 )
 import homeassistant.helpers.config_validation as cv
@@ -281,7 +282,7 @@ class WirelessTagBaseSensor(Entity):
         return {
             ATTR_BATTERY_LEVEL: int(self._tag.battery_remaining * 100),
             ATTR_VOLTAGE: f"{self._tag.battery_volts:.2f}{VOLT}",
-            ATTR_TAG_SIGNAL_STRENGTH: f"{self._tag.signal_strength}dBm",
+            ATTR_TAG_SIGNAL_STRENGTH: f"{self._tag.signal_strength}{SIGNAL_STRENGTH_DECIBELS_MILLIWATT}",
             ATTR_TAG_OUT_OF_RANGE: not self._tag.is_in_range,
             ATTR_TAG_POWER_CONSUMPTION: f"{self._tag.power_consumption:.2f}{PERCENTAGE}",
         }
diff --git a/homeassistant/components/wled/const.py b/homeassistant/components/wled/const.py
index 6006952a5801..f50e17c01cca 100644
--- a/homeassistant/components/wled/const.py
+++ b/homeassistant/components/wled/const.py
@@ -26,7 +26,6 @@ ATTR_UDP_PORT = "udp_port"
 
 # Units of measurement
 CURRENT_MA = "mA"
-SIGNAL_DBM = "dBm"
 
 # Services
 SERVICE_EFFECT = "effect"
diff --git a/homeassistant/components/wled/sensor.py b/homeassistant/components/wled/sensor.py
index 63a253e6efc1..06445d03ba94 100644
--- a/homeassistant/components/wled/sensor.py
+++ b/homeassistant/components/wled/sensor.py
@@ -10,13 +10,14 @@ from homeassistant.const import (
     DEVICE_CLASS_SIGNAL_STRENGTH,
     DEVICE_CLASS_TIMESTAMP,
     PERCENTAGE,
+    SIGNAL_STRENGTH_DECIBELS_MILLIWATT,
 )
 from homeassistant.helpers.entity import Entity
 from homeassistant.helpers.typing import HomeAssistantType
 from homeassistant.util.dt import utcnow
 
 from . import WLEDDataUpdateCoordinator, WLEDDeviceEntity
-from .const import ATTR_LED_COUNT, ATTR_MAX_POWER, CURRENT_MA, DOMAIN, SIGNAL_DBM
+from .const import ATTR_LED_COUNT, ATTR_MAX_POWER, CURRENT_MA, DOMAIN
 
 _LOGGER = logging.getLogger(__name__)
 
@@ -192,7 +193,7 @@ class WLEDWifiRSSISensor(WLEDSensor):
             icon="mdi:wifi",
             key="wifi_rssi",
             name=f"{coordinator.data.info.name} Wi-Fi RSSI",
-            unit_of_measurement=SIGNAL_DBM,
+            unit_of_measurement=SIGNAL_STRENGTH_DECIBELS_MILLIWATT,
         )
 
     @property
diff --git a/homeassistant/const.py b/homeassistant/const.py
index f845bc2bd0f0..6099a28a7c81 100644
--- a/homeassistant/const.py
+++ b/homeassistant/const.py
@@ -472,6 +472,10 @@ SPEED_METERS_PER_SECOND = f"{LENGTH_METERS}/{TIME_SECONDS}"
 SPEED_KILOMETERS_PER_HOUR = f"{LENGTH_KILOMETERS}/{TIME_HOURS}"
 SPEED_MILES_PER_HOUR = "mph"
 
+# Signal_strength units
+SIGNAL_STRENGTH_DECIBELS = "dB"
+SIGNAL_STRENGTH_DECIBELS_MILLIWATT = "dBm"
+
 # Data units
 DATA_BITS = "bit"
 DATA_KILOBITS = "kbit"
diff --git a/tests/components/canary/test_sensor.py b/tests/components/canary/test_sensor.py
index c17db7b88c90..d32741d3705e 100644
--- a/tests/components/canary/test_sensor.py
+++ b/tests/components/canary/test_sensor.py
@@ -15,6 +15,7 @@ from homeassistant.const import (
     DEVICE_CLASS_SIGNAL_STRENGTH,
     DEVICE_CLASS_TEMPERATURE,
     PERCENTAGE,
+    SIGNAL_STRENGTH_DECIBELS_MILLIWATT,
     TEMP_CELSIUS,
 )
 from homeassistant.setup import async_setup_component
@@ -187,7 +188,7 @@ async def test_sensors_flex(hass, canary) -> None:
         "home_dining_room_wifi": (
             "20_wifi",
             "-57.0",
-            "dBm",
+            SIGNAL_STRENGTH_DECIBELS_MILLIWATT,
             DEVICE_CLASS_SIGNAL_STRENGTH,
             None,
         ),
diff --git a/tests/components/huawei_lte/test_sensor.py b/tests/components/huawei_lte/test_sensor.py
index f98343497503..92bb8cbac5e0 100644
--- a/tests/components/huawei_lte/test_sensor.py
+++ b/tests/components/huawei_lte/test_sensor.py
@@ -3,11 +3,19 @@
 import pytest
 
 from homeassistant.components.huawei_lte import sensor
+from homeassistant.const import (
+    SIGNAL_STRENGTH_DECIBELS,
+    SIGNAL_STRENGTH_DECIBELS_MILLIWATT,
+)
 
 
 @pytest.mark.parametrize(
     ("value", "expected"),
-    (("-71 dBm", (-71, "dBm")), ("15dB", (15, "dB")), (">=-51dBm", (-51, "dBm"))),
+    (
+        ("-71 dBm", (-71, SIGNAL_STRENGTH_DECIBELS_MILLIWATT)),
+        ("15dB", (15, SIGNAL_STRENGTH_DECIBELS)),
+        (">=-51dBm", (-51, SIGNAL_STRENGTH_DECIBELS_MILLIWATT)),
+    ),
 )
 def test_format_default(value, expected):
     """Test that default formatter copes with expected values."""
diff --git a/tests/components/rfxtrx/test_sensor.py b/tests/components/rfxtrx/test_sensor.py
index c1bb3222b790..77f9960de49e 100644
--- a/tests/components/rfxtrx/test_sensor.py
+++ b/tests/components/rfxtrx/test_sensor.py
@@ -3,7 +3,12 @@ import pytest
 
 from homeassistant.components.rfxtrx import DOMAIN
 from homeassistant.components.rfxtrx.const import ATTR_EVENT
-from homeassistant.const import ATTR_UNIT_OF_MEASUREMENT, PERCENTAGE, TEMP_CELSIUS
+from homeassistant.const import (
+    ATTR_UNIT_OF_MEASUREMENT,
+    PERCENTAGE,
+    SIGNAL_STRENGTH_DECIBELS_MILLIWATT,
+    TEMP_CELSIUS,
+)
 from homeassistant.core import State
 
 from tests.common import MockConfigEntry, mock_restore_cache
@@ -100,7 +105,10 @@ async def test_one_sensor_no_datatype(hass, rfxtrx):
     assert state
     assert state.state == "unknown"
     assert state.attributes.get("friendly_name") == f"{base_name} Rssi numeric"
-    assert state.attributes.get(ATTR_UNIT_OF_MEASUREMENT) == "dBm"
+    assert (
+        state.attributes.get(ATTR_UNIT_OF_MEASUREMENT)
+        == SIGNAL_STRENGTH_DECIBELS_MILLIWATT
+    )
 
     state = hass.states.get(f"{base_id}_battery_numeric")
     assert state
@@ -174,7 +182,10 @@ async def test_discover_sensor(hass, rfxtrx_automatic):
     state = hass.states.get(f"{base_id}_rssi_numeric")
     assert state
     assert state.state == "-64"
-    assert state.attributes.get(ATTR_UNIT_OF_MEASUREMENT) == "dBm"
+    assert (
+        state.attributes.get(ATTR_UNIT_OF_MEASUREMENT)
+        == SIGNAL_STRENGTH_DECIBELS_MILLIWATT
+    )
 
     state = hass.states.get(f"{base_id}_temperature")
     assert state
@@ -203,7 +214,10 @@ async def test_discover_sensor(hass, rfxtrx_automatic):
     state = hass.states.get(f"{base_id}_rssi_numeric")
     assert state
     assert state.state == "-64"
-    assert state.attributes.get(ATTR_UNIT_OF_MEASUREMENT) == "dBm"
+    assert (
+        state.attributes.get(ATTR_UNIT_OF_MEASUREMENT)
+        == SIGNAL_STRENGTH_DECIBELS_MILLIWATT
+    )
 
     state = hass.states.get(f"{base_id}_temperature")
     assert state
@@ -232,7 +246,10 @@ async def test_discover_sensor(hass, rfxtrx_automatic):
     state = hass.states.get(f"{base_id}_rssi_numeric")
     assert state
     assert state.state == "-64"
-    assert state.attributes.get(ATTR_UNIT_OF_MEASUREMENT) == "dBm"
+    assert (
+        state.attributes.get(ATTR_UNIT_OF_MEASUREMENT)
+        == SIGNAL_STRENGTH_DECIBELS_MILLIWATT
+    )
 
     state = hass.states.get(f"{base_id}_temperature")
     assert state
@@ -315,13 +332,19 @@ async def test_rssi_sensor(hass, rfxtrx):
     assert state
     assert state.state == "unknown"
     assert state.attributes.get("friendly_name") == "PT2262 22670e Rssi numeric"
-    assert state.attributes.get(ATTR_UNIT_OF_MEASUREMENT) == "dBm"
+    assert (
+        state.attributes.get(ATTR_UNIT_OF_MEASUREMENT)
+        == SIGNAL_STRENGTH_DECIBELS_MILLIWATT
+    )
 
     state = hass.states.get("sensor.ac_213c7f2_48_rssi_numeric")
     assert state
     assert state.state == "unknown"
     assert state.attributes.get("friendly_name") == "AC 213c7f2:48 Rssi numeric"
-    assert state.attributes.get(ATTR_UNIT_OF_MEASUREMENT) == "dBm"
+    assert (
+        state.attributes.get(ATTR_UNIT_OF_MEASUREMENT)
+        == SIGNAL_STRENGTH_DECIBELS_MILLIWATT
+    )
 
     await rfxtrx.signal("0913000022670e013b70")
     await rfxtrx.signal("0b1100cd0213c7f230010f71")
diff --git a/tests/components/wled/test_sensor.py b/tests/components/wled/test_sensor.py
index 39cde51dbfd5..d5c1c738d2f3 100644
--- a/tests/components/wled/test_sensor.py
+++ b/tests/components/wled/test_sensor.py
@@ -12,7 +12,6 @@ from homeassistant.components.wled.const import (
     ATTR_MAX_POWER,
     CURRENT_MA,
     DOMAIN,
-    SIGNAL_DBM,
 )
 from homeassistant.const import (
     ATTR_DEVICE_CLASS,
@@ -20,6 +19,7 @@ from homeassistant.const import (
     ATTR_UNIT_OF_MEASUREMENT,
     DATA_BYTES,
     PERCENTAGE,
+    SIGNAL_STRENGTH_DECIBELS_MILLIWATT,
 )
 from homeassistant.core import HomeAssistant
 from homeassistant.util import dt as dt_util
@@ -138,7 +138,10 @@ async def test_sensors(
     state = hass.states.get("sensor.wled_rgb_light_wifi_rssi")
     assert state
     assert state.attributes.get(ATTR_ICON) == "mdi:wifi"
-    assert state.attributes.get(ATTR_UNIT_OF_MEASUREMENT) == SIGNAL_DBM
+    assert (
+        state.attributes.get(ATTR_UNIT_OF_MEASUREMENT)
+        == SIGNAL_STRENGTH_DECIBELS_MILLIWATT
+    )
     assert state.state == "-62"
 
     entry = registry.async_get("sensor.wled_rgb_light_wifi_rssi")
diff --git a/tests/testing_config/custom_components/test/sensor.py b/tests/testing_config/custom_components/test/sensor.py
index d9ed47844afe..d467a93fd621 100644
--- a/tests/testing_config/custom_components/test/sensor.py
+++ b/tests/testing_config/custom_components/test/sensor.py
@@ -4,7 +4,7 @@ Provide a mock sensor platform.
 Call init before using it in your tests to ensure clean test data.
 """
 import homeassistant.components.sensor as sensor
-from homeassistant.const import PERCENTAGE, PRESSURE_HPA
+from homeassistant.const import PERCENTAGE, PRESSURE_HPA, SIGNAL_STRENGTH_DECIBELS
 
 from tests.common import MockEntity
 
@@ -15,7 +15,7 @@ UNITS_OF_MEASUREMENT = {
     sensor.DEVICE_CLASS_BATTERY: PERCENTAGE,  # % of battery that is left
     sensor.DEVICE_CLASS_HUMIDITY: PERCENTAGE,  # % of humidity in the air
     sensor.DEVICE_CLASS_ILLUMINANCE: "lm",  # current light level (lx/lm)
-    sensor.DEVICE_CLASS_SIGNAL_STRENGTH: "dB",  # signal strength (dB/dBm)
+    sensor.DEVICE_CLASS_SIGNAL_STRENGTH: SIGNAL_STRENGTH_DECIBELS,  # signal strength (dB/dBm)
     sensor.DEVICE_CLASS_TEMPERATURE: "C",  # temperature (C/F)
     sensor.DEVICE_CLASS_TIMESTAMP: "hh:mm:ss",  # timestamp (ISO8601)
     sensor.DEVICE_CLASS_PRESSURE: PRESSURE_HPA,  # pressure (hPa/mbar)