Marine City is in St. Clair County, and in the Southeast Region (part of the Detroit, Michigan metropolitan area). This community is located between Algonac and St Clair on State Hwy 29 at the mouth of the Belle River.

Marine City was first called Yankee Point because it was first settled by eastern Yankees. This City is one of three international crossings to Canada in St. Clair County. It has regular car and passenger ferry service to Sombra, Ontario.