The Mutual Life Building, originally known as the Yesler Building, is an historic office building located in Seattle's Pioneer Square neighborhood that anchors the West side of the square. The building sits on one of the most historic sites in the city; the original location of Henry Yesler's cookhouse that served his sawmill in the early 1850s and was one of Seattle's first community gathering spaces. It was also the site of the first sermon delivered and first lawsuit tried in King County. By the late 1880s Yesler had replaced the old shanties with several substantial brick buildings including the grand Yesler-Leary Building, which would all be destroyed by the Great Seattle Fire in 1889.

The realignment of First Avenue to reconcile Seattle's clashing street grids immediately after the fire would split Yesler's corner into two pieces; the severed eastern corner would become part of Pioneer Square park, and on the western lot Yesler would begin construction of his eponymous block in 1890 to house the First National Bank, which had previously been located in the Yesler-Leary Building. Portland brewer Louis Feurer began construction of a conjoined building to the west of Yesler's at the same time.

Progress of both would be stunted and the original plans of architect Elmer H. Fisher were dropped by the time construction resumed in 1892. It would take 4 phases and 4 different architects before the building reached its final form in 1905. The Mutual Life Insurance Company of New York only owned the building from 1896 to 1909, but it would retain their name even after the company moved out in 1916.

Though well maintained as an office building into the 1940s under the ownership of the Shafer Brothers, by the 1950s the building was largely vacant and deteriorating, becoming a poster child of the blight facing the Pioneer Square neighborhood and in the early 1960s was recognized as one of the most historically significant buildings on the square. The building became the birthplace of Seattle's historic preservation movement and was listed on the National Register of Historic Places in 1970 as a contributing property in the Pioneer Square Historic District but was not fully restored until the early 1980s, which returned its use to office space.