The Hocking River (formerly the Hockhocking River) is a 102-mile-long (164 km) right tributary of the Ohio River in southeastern Ohio in the United States. The Hocking flows mostly on the unglaciated Allegheny Plateau, but its headwaters are in a glaciated region. It rises in Bloom Township in Fairfield County and flows generally southeastwardly through Fairfield, Hocking, and Athens counties, through the Hocking Hills region and past the cities of Lancaster, Logan, Nelsonville, Athens and Coolville. It joins the Ohio River at Hockingport. The Hocking's tributaries also drain parts of Perry, Morgan, and Washington Counties.