Essexville is a city in Bay County in the U.S. state of Michigan. The population was 3,379 at the 2020 census. Located along the Sagina…Essexville is a city in Bay County in the U.S. state of Michigan. The population was 3,379 at the 2020 census. Located along the Saginaw River, Essexville is part of the Saginaw, Midland, and Bay City metropolitan area.