The Tuscarawas, colloquially the Tusk, is a medium-sized river in northeastern Ohio, an important tributary of the Muskingum. The headwaters rise in Stark County, a few miles southeast of Hartville. It first flows west, through the Portage Lakes area. In Barberton, the river turns southward and the former path of the Ohio and Erie Canal runs side by side with the river for much of its length. The Tuscarawas continues through (among other places) Clinton, Canal Fulton, Massillon, Navarre, Bolivar, Zoarville , Dover, New Philadelphia, Gnadenhutten, Port Washington, Newcomerstown before joining the Walhonding River to form the Muskingum near Coshocton.

Tributaries include the Chippewa Creek, Sandy Creek, Conotton Creek, Sugar Creek, and Stillwater Creek.

In places the Tusk is connected to the Ohio and Erie Canal and feeds the canal with water, particularly in Stark County.