Green Bay ( green BAY) is a city in the U.S. state of Wisconsin. The county seat of Brown County, it is at the head of Green Bay (known locally as "the bay of Green Bay"), a sub-basin of Lake Michigan at the mouth of the Fox River. As of the 2020 Census, Green Bay had a population of 107,395, making it the third-most populous city in Wisconsin, after Milwaukee and Madison, and the third-largest city on Lake Michigan, after Chicago and Milwaukee. Green Bay is the principal city of the Green Bay Metropolitan Statistical Area, which covers Brown, Kewaunee, and Oconto counties. Green Bay is the home city of the National Football League (NFL)'s Green Bay Packers.