Lake Morton-Berrydale is a census-designated place (CDP) in King County, Washington, United States.

Lake Morton-Berrydale is located in southwestern King County and is bordered to the west by the city of Auburn, to the northwest by Kent, to the north by Covington, to the northeast by Maple Valley, to the east by Black Diamond, and to the south by the Lake Holm CDP.

The namesake water body of Lake Morton is in the eastern part of the CDP, and the unincorporated community of Berrydale is in the northwest.

Washington State Route 18 forms the northwest border of the CDP, and leads northeast 17 miles (27 km) to Interstate 90 near Snoqualmie and southwest 6 miles (10 km) to Auburn.

11.6% of all households were made up of individuals, and 2.6% had someone living alone who was 65 years of age or older.