diff --git a/esphome/components/thermostat/climate.py b/esphome/components/thermostat/climate.py
index 9a57f6a337..cca46609db 100644
--- a/esphome/components/thermostat/climate.py
+++ b/esphome/components/thermostat/climate.py
@@ -591,11 +591,11 @@ CONFIG_SCHEMA = cv.All(
             cv.Optional(CONF_DEFAULT_TARGET_TEMPERATURE_LOW): cv.temperature,
             cv.Optional(
                 CONF_SET_POINT_MINIMUM_DIFFERENTIAL, default=0.5
-            ): cv.temperature,
-            cv.Optional(CONF_COOL_DEADBAND, default=0.5): cv.temperature,
-            cv.Optional(CONF_COOL_OVERRUN, default=0.5): cv.temperature,
-            cv.Optional(CONF_HEAT_DEADBAND, default=0.5): cv.temperature,
-            cv.Optional(CONF_HEAT_OVERRUN, default=0.5): cv.temperature,
+            ): cv.temperature_delta,
+            cv.Optional(CONF_COOL_DEADBAND, default=0.5): cv.temperature_delta,
+            cv.Optional(CONF_COOL_OVERRUN, default=0.5): cv.temperature_delta,
+            cv.Optional(CONF_HEAT_DEADBAND, default=0.5): cv.temperature_delta,
+            cv.Optional(CONF_HEAT_OVERRUN, default=0.5): cv.temperature_delta,
             cv.Optional(CONF_MAX_COOLING_RUN_TIME): cv.positive_time_period_seconds,
             cv.Optional(CONF_MAX_HEATING_RUN_TIME): cv.positive_time_period_seconds,
             cv.Optional(CONF_MIN_COOLING_OFF_TIME): cv.positive_time_period_seconds,
@@ -608,8 +608,8 @@ CONFIG_SCHEMA = cv.All(
             cv.Optional(CONF_MIN_HEATING_OFF_TIME): cv.positive_time_period_seconds,
             cv.Optional(CONF_MIN_HEATING_RUN_TIME): cv.positive_time_period_seconds,
             cv.Required(CONF_MIN_IDLE_TIME): cv.positive_time_period_seconds,
-            cv.Optional(CONF_SUPPLEMENTAL_COOLING_DELTA): cv.temperature,
-            cv.Optional(CONF_SUPPLEMENTAL_HEATING_DELTA): cv.temperature,
+            cv.Optional(CONF_SUPPLEMENTAL_COOLING_DELTA): cv.temperature_delta,
+            cv.Optional(CONF_SUPPLEMENTAL_HEATING_DELTA): cv.temperature_delta,
             cv.Optional(
                 CONF_FAN_ONLY_ACTION_USES_FAN_MODE_TIMER, default=False
             ): cv.boolean,
diff --git a/esphome/config_validation.py b/esphome/config_validation.py
index 3720757828..ed87e98078 100644
--- a/esphome/config_validation.py
+++ b/esphome/config_validation.py
@@ -929,6 +929,27 @@ def temperature(value):
     raise err
 
 
+def temperature_delta(value):
+    err = None
+    try:
+        return _temperature_c(value)
+    except Invalid as orig_err:
+        err = orig_err
+
+    try:
+        return _temperature_k(value)
+    except Invalid:
+        pass
+
+    try:
+        fahrenheit = _temperature_f(value)
+        return fahrenheit * (5 / 9)
+    except Invalid:
+        pass
+
+    raise err
+
+
 _color_temperature_mireds = float_with_unit("Color Temperature", r"(mireds|Mireds)")
 _color_temperature_kelvin = float_with_unit("Color Temperature", r"(K|Kelvin)")