St. Louis Bay Bridge, Road bridge over the Bay of Saint Louis between Bay St. Louis and Pass Christian, Mississippi, United States

The St. Louis Bay Bridge is a road viaduct spanning the Bay of Saint Louis and connecting Bay St. Louis and Pass Christian in Mississippi. The four-lane structure carries U.S. Route 90 traffic and includes a dedicated pedestrian and cycling path on the Gulf side.

The original bridge carrying U.S. Route 90 over the Bay of Saint Louis was heavily damaged by Hurricane Katrina in August 2005. Its replacement opened to traffic on May 17, 2007, restoring the crossing between Bay St. Louis and Pass Christian.

The pedestrian and cycling path on the Gulf side allows visitors to cross the bay on foot or by bicycle while enjoying water views. This passage was deliberately built into the structure to help people connect with the local coastal landscape.

Four-lane traffic moves across the structure in steady flow, especially during morning and evening rush periods. Pedestrians and cyclists can use the separate path and should prepare for sun exposure and changing weather conditions.

The bridge that opened on May 17, 2007, replaced a span heavily damaged by Hurricane Katrina in August 2005. Its 12-foot path runs along the Gulf side, so walkers and cyclists cross on the open-water edge rather than between the traffic lanes.