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 (CDP) 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 (14 km) north of Ann Arbor and about 9 miles (14 km) 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.
The Whitmore Lake post office, with ZIP code 48189, serves a larger area than that defined by the CDP and includes portions of southeast Hamburg Township, northeastern Webster Township, and larger parts of Green Oak and Northfield Townships than are included in the CDP.
The 667-acre (2.70 km2) Whitmore Lake was named by Jonathan F. Stratton, a surveyor, after Luke H. Whitmore, a local landowner around 1825. Area residents have considered incorporation many times, but have not chosen to do so yet.
The well-known 8 Mile Road that forms the boundary between the city of Detroit and Detroit's northern suburbs in Oakland and Macomb counties ends in Whitmore Lake, along with 5 Mile, 6 Mile, 7 Mile, and 9 Mile Roads.