Whitmore Lake is a census-designated place and unincorporated community in the U.S. state of Michigan. The community spans the boundary between Green Oak Township in Livingston County and Northfield Township in Washtenaw County. The United States Census Bureau has defined a census-designated place with this name for statistical purposes, which has no legal status as an incorporated municipality. The population was 6,423 at the 2010 census.The community is located about 9 miles north of Ann Arbor and about 9 miles south of Brighton. It is situated around the shores of Whitmore Lake, and the CDP also includes the area around the smaller Horseshoe Lake to the south, Lawton Lake to the east and Monahan Lake to the northeast. U.S. Highway 23 forms the western edge of much of the CDP.