Montlake Bridge, Double-leaf bascule bridge in Montlake, United States

Montlake Bridge is a double-leaf bascule bridge that crosses the Lake Washington Ship Canal and joins the Montlake neighborhood with the University District. The structure carries vehicles, pedestrians, and bicycles on its decks while allowing tall sailing vessels to pass beneath when the two leaves raise vertically.

The bridge opened in 1925 as the final addition to a series of bascule bridges built for the newly developed ship canal. It was constructed to serve growing traffic between neighborhoods while accommodating commercial and recreational boat traffic.

Since 1925 the bridge has hosted the opening-day festivities of Seattle's boating season on the first Saturday in May. The bridge and the Montlake Cut together form a City of Seattle Designated Landmark (ID 107995).

The bridge has sidewalks on both sides for pedestrians and cyclists. It does not open during morning and evening rush hours; it opens on the hour and half-hour just before and after rush periods, and on demand at other times. Openings average four minutes. Most are for sailboats, since most tugs this far east pass under the closed span.

The bridge's trunnion supports were a deliberate workaround: the Strauss Bascule Bridge Company held patents on the Chicago bascule design, so Seattle's engineers used trunnions to avoid an infringement suit. It is one of six Seattle bridges derived from that Chicago design, and the only one built this way.