The Jefferson Barracks Bridge, often called the J.B. Bridge, is a pair of bridges that span the Mississippi River on the south side of St. Louis, Missouri. Both bridges are 909-foot (277 m) long steel arch bridges. The first bridge was built in 1983, the south bridge opened in 1992. A delay occurred during the construction of the second bridge when a crane dropped a section of it into the river and it had to be rebuilt.
They replaced the former steel truss bridge built in 1941 that originally carried U.S. Route 50. It carries traffic for Interstate 255 (part of the St. Louis beltway) and U.S. Route 50. Prior to the construction of the first bridge, river crossings in this area were made via the Davis Street Ferry in the Carondelet neighborhood of St. Louis.