diff --git a/homeassistant/components/modbus/__init__.py b/homeassistant/components/modbus/__init__.py
index dc53b849861..cfe0aa370fe 100644
--- a/homeassistant/components/modbus/__init__.py
+++ b/homeassistant/components/modbus/__init__.py
@@ -42,6 +42,7 @@ from homeassistant.const import (
     CONF_TEMPERATURE_UNIT,
     CONF_TIMEOUT,
     CONF_TYPE,
+    CONF_UNIQUE_ID,
     CONF_UNIT_OF_MEASUREMENT,
 )
 from homeassistant.core import HomeAssistant
@@ -122,6 +123,7 @@ BASE_COMPONENT_SCHEMA = vol.Schema(
             CONF_SCAN_INTERVAL, default=DEFAULT_SCAN_INTERVAL
         ): cv.positive_int,
         vol.Optional(CONF_LAZY_ERROR, default=0): cv.positive_int,
+        vol.Optional(CONF_UNIQUE_ID): cv.string,
     }
 )
 
diff --git a/homeassistant/components/modbus/base_platform.py b/homeassistant/components/modbus/base_platform.py
index 682b3430807..615e86ae920 100644
--- a/homeassistant/components/modbus/base_platform.py
+++ b/homeassistant/components/modbus/base_platform.py
@@ -20,6 +20,7 @@ from homeassistant.const import (
     CONF_SCAN_INTERVAL,
     CONF_SLAVE,
     CONF_STRUCTURE,
+    CONF_UNIQUE_ID,
     STATE_ON,
 )
 from homeassistant.core import callback
@@ -82,6 +83,7 @@ class BasePlatform(Entity):
         self._cancel_timer: Callable[[], None] | None = None
         self._cancel_call: Callable[[], None] | None = None
 
+        self._attr_unique_id = entry.get(CONF_UNIQUE_ID)
         self._attr_name = entry[CONF_NAME]
         self._attr_should_poll = False
         self._attr_device_class = entry.get(CONF_DEVICE_CLASS)