Big Black River is a river in the U.S. state of
Mississippi and a tributary of the Mississippi River. Its origin is in
Webster County near the town of
Eupora in the north central part of the state. From there it flows in a generally southwest direction until it merges with the Mississippi River south of the city of
Vicksburg. It is the major contributor to the Big Black River Basin. It forms the eastern border of
Holmes County, the northern border of
Choctaw County, and the northern border of
Claiborne County.