Old Vicksburg Bridge, Railroad bridge in Vicksburg, United States.

The Old Vicksburg Bridge is a steel cantilever and truss bridge over the Mississippi River between Delta, Louisiana, and Vicksburg, Mississippi. Its 948 m of trusses include a 507.5 m Gerber span with a main span of 251.5 m, plus three Parker truss spans; approach girder bridges run about 1.5 km. The dark crisscross members rest on tall rectangular concrete piers, and a small American flag flies from the rightmost peak.

Designed by Harrington, Howard & Ash for the Vicksburg Bridge & Terminal Company, the bridge was built between 1928 and 1930 to replace a rail ferry that had carried about 100,000 railcars a year. It opened in 1930 as a combined rail and road crossing, carrying U.S. Highway 80 alongside the single track. Warren County bought it in 1947, and it was listed on the National Register of Historic Places in 1989.

The bridge is named for Vicksburg and is also called the Mississippi River Bridge. It is managed by Warren County and used by the Kansas City Southern Railway. A small American flag flies from a pole atop the rightmost peak of the steel truss.

The bridge carries only the Kansas City Southern rail line, so there is no pedestrian or vehicle access across it; the single road lane inside the truss is reserved for worker inspection. Views of the truss and its concrete piers are had from the riverbanks at Vicksburg and Delta.

Trucks crossing the bridge had to stop at railroad-style signal towers at each end, then use the full width of both narrow lanes alone; crossings were limited to daylight hours. The road deck was only 5.5 m wide, about 2 m per direction, which led to the closure of vehicle traffic in 1998.