Northwest Seaport, Maritime museum at South Lake Union waterfront, Seattle, United States

Northwest Seaport is a maritime museum on the South Lake Union waterfront in Seattle, Washington, where historic wooden vessels and fishing boats are kept moored at the docks. Most of the collection sits directly in the water, so visitors can walk along the pier and see the boats up close.

Northwest Seaport began in the early 1960s as the Save Our Ships project, formed to rescue the 1897 Pacific schooner Wawona. The group bought Wawona in 1964, acquired Lightship 83 in 1966, and received the tugboat Arthur Foss as a donation from the Foss company in 1970. Based in Kirkland through the 1970s, it was renamed Northwest Seaport and moved to Lake Union in the early 1980s.

The fleet includes the tugboat Arthur Foss, built in 1889 and cast by MGM in the 1933 film Tugboat Annie; it was the last vessel to escape Wake Island before the December 1941 battle. The lightship Swiftsure, launched in 1904, saved 150 people at Blunts Reef in 1904–1905. Programs range from toddler story times to maritime music sing-alongs and vocational training in the marine trades.

The ships are moored at the Historic Ships' Wharf on the south shore of Lake Union, beside the Center for Wooden Boats and the Museum of History and Industry; the three organizations share the park but are separate. Access to the wharf is on foot through Lake Union Park.

The fleet's oldest hull is the tugboat Arthur Foss, built in 1889 and the oldest wooden-hulled tugboat still afloat in the United States. In 1898 she towed barges of miners and supplies up the Inside Passage during the Klondike Gold Rush, and in 1933 MGM cast her as Tugboat Annie.