Salmon Bay Bridge, Railway bridge in Magnolia, Seattle, United States.

Salmon Bay Bridge is a Strauss heel-trunnion single-leaf bascule railway bridge spanning Salmon Bay between Magnolia/Interbay and Ballard in Seattle. Its 61-meter opening span carries two tracks of the BNSF Scenic Subdivision, with 13.1 meters of vessel clearance at mean high tide when lowered.

The bridge was built in 1914 by Great Northern Railway to establish a rail connection across Salmon Bay. This construction was a key step in developing Seattle's railroad network and industrial accessibility.

The bridge appears on the crest of Salmon Bay FC, a semi-professional soccer team in the USL W League. Its name also marks the water it crosses, Salmon Bay, the western part of the Lake Washington Ship Canal just before Puget Sound. The Strauss heel-trunnion bascule design by Joseph Baermann Strauss, later known for the Golden Gate Bridge, is a detail visible in the moving leaf.

The bridge sits just west of Commodore Park and the Hiram M. Chittenden Locks, so the locks' grounds and the Ballard shoreline give the closest views of the span and its counterweight. Around 30 to 40 trains cross daily, and the bascule leaf lifts for vessels heading out of the locks into Puget Sound.

The bridge's lifting mechanism rarely operates in full view, as fewer ships pass beneath it compared to earlier decades. Witnessing the bridge raise is an uncommon moment that many visitors miss entirely.