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 330 miles (530 km) in a generally southwest direction until it merges with the Mississippi River 25 miles (40 km) south of the city of Vicksburg.
The Big Black River and most of its tributaries are silt-filled. The rivers carry large amounts of suspended sediment, resulting mostly from agricultural runoff. These tributaries are mostly slow-flowing muddy streams, however some are swift-flowing with sandy bottoms.
