Ballard Bridge, Double-leaf bascule bridge in Seattle, United States.

Ballard Bridge, also called the 15th Avenue Bridge, is a double-leaf bascule bridge in Seattle, Washington, carrying 15th Avenue Northwest over Salmon Bay between Ballard to the north and Interbay to the south. It opened in 1917 with an opening span of 218 ft (66 m) and a total length of 2,854 ft (870 m). It is one of the succession of bridges spanning the Lake Washington Ship Canal.

The bridge opened in 1917 while the Lake Washington Ship Canal was still under construction, replacing earlier wooden crossings that had served Salmon Bay since the late 1800s. It was part of a broader effort to open Seattle's inner waterways to larger commercial vessels.

The bridge appears on the crest of Ballard FC, a semi-professional soccer team in USL League Two, and its largest supporters' group is called the Bridge Keepers after the span. The 15th Avenue Bridge is the bridge's other name.

The bridge opens for boats, so drivers and pedestrians should expect short waits; in 2024, seismic work with ground anchors closed it to vehicles over several weekends in September and October. Bicyclists have raised safety concerns about the crossing in recent years.

The bridge appears on the crest of Ballard FC, a semi-professional soccer team in USL League Two, and its largest supporters' group is called the Bridge Keepers after the span. The 1917 crossing also carried a streetcar until the rails were removed in 1939, when the timber approach spans were replaced as a Public Works Administration project.