South Gull Lake is a census-designated place in Ross Township, Kalamazoo County, in the U.S. state of Michigan. It includes the unincorporated communities of Yorkville, Gull Lake, and Midland Park and does not have any legal status as an incorporated municipality. The population of the CDP was 1,182 at the 2010 census, down from 1,526 at the 2000 census.