Union City is a village in Branch and Calhoun counties in the U.S. state of Michigan. Located mostly within Union Township in Branch County, it sits at the junction of the Coldwater and St. Joseph rivers; the Calhoun County portion lies within that county's Burlington Township. It is part of the Battle Creek, Michigan Metropolitan Statistical Area. The population was 1,804 at the 2000 census. M-60 passes just north of the village. The village is home to a clothing optional park, Turtle Lake Resort.