Harpeth River State Park is a state park in Cheatham and Davidson counties in the U.S. state of Tennessee, in the southeastern United States. The park is a linear park that was created to connect several state historic, natural, and archaeological sites along the lower Harpeth River. The park includes an incised meander in the river known as the Narrows of the Harpeth and its associated national historic landmark, the Montgomery Bell Tunnel.