The Obey River is a tributary of the Cumberland River which has its confluence with the larger stream near the town of Celina, Tennessee which is generally considered to be the Cumberland's head of navigation.

Near its mouth, the Obey is impounded by the U.S. Army Corps of Engineers Dale Hollow Dam , site of a fish hatchery run by the federal government. This dam empounds the Obey for essentially its entire length, causing slack water well up both major tributaries, the East and West Forks. This lake is relatively deep due to the height of the dam and the depth of the gorges through which the Obey and its tributaries flowed; the empoundment also enters Kentucky in its Wolf River and Sulphur Creek embayments.

Below the dam the stream makes two sharp bends before entering the Cumberland. The only major bridge on the Obey, on Tennessee Highway 53, is located just below the second of these, Peterman Bend.