The Fox River is a river in eastern and central Wisconsin in the United States. Along the banks is a chain of cities and villages, including Oshkosh, Neenah, Menasha, Appleton, Little Chute, Kimberly, Combined Locks, and Kaukauna. Except for Oshkosh, located on the Upper Fox River near Lake Winnebago, these cities and villages identify as the Fox Cities. Further north along the Lower Fox River, from its outlet from Lake Winnebago and before its mouth at Lake Michigan, are the cities of De Pere and Green Bay (located at the lake), and the villages of Ashwaubenon and Allouez; although they are in the Fox River Valley, this grouping of cities and villages does not refer to themselves as Fox Cities.

Fox River is an unincorporated community located in the town of Salem, Kenosha County, Wisconsin, United States.