Grass Lake is a village in Jackson County in the U.S. state of Michigan. The population was 1,082 at the 2000 census. In 1842 the Michigan Central Railroad bypassed the original village and built a depot 1.5 miles to the west. The village was relocated to this new location - its current location - to be closer to the rail depot. Grass Lake was named for the shallow, marshy lake just to its north. Today the greater Grass Lake area includes the Village of Grass Lake, Grass Lake Township, and parts of the Waterloo Recreational Area north of I-94.