The Tuskaloosa darter (Etheostoma douglasi) is a species of fish in the perch family endemic to Alabama in the United States, where it occurs only in the upper Black Warrior River drainage, with disjunct populations occurring in the Locust Fork system and upper Sipsey Fork systems. This fish inhabits rocky riffles of creeks and small to medium rivers. Adults typically occur in riffles of streams with moderate to strong current over gravel or cobble substrate.