County Line is an unincorporated community located on the border of Marinette and Oconto counties, in the U.S. state of Wisconsin. The Marinette County portion of the community is located in the town of Grover, while the Oconto County portion is located in the town of Little River. County Line is located on County Trunk Highway W near U.S. Highway 41, 6.5 miles (10.5 km) southwest of Peshtigo.