Grass Lake is a village in Jackson County in the U.S. state of Michigan. The population was 1,105 at the 2020 census. The village is located just south of Interstate 94 in Grass Lake Township.

Jackson County is located in the U.S. state of Michigan. The population of the county was 160,366 as of the 2020 Census. Its seat of government is the city of Jackson. The county was set off in 1829 and organized in 1832. It is named for U.S. President Andrew Jackson and considered to be one of Michigan's "Cabinet counties", named for members of Jackson's Cabinet.