Berrien County is a county in the U.S. state of Michigan. It is located at the southwest corner of the state's Lower Peninsula, located on the shore of Lake Michigan and sharing a land border with Indiana. As of the 2020 Census, the population was 154,316. The county seat is St. Joseph. Berrien County is included in the Niles-Benton Harbor, MI Metropolitan Statistical Area, which is also included in the South Bend-Elkhart-Mishawaka, IN-MI Combined Statistical Area.