Southern Pacific Building, Historical skyscraper in Financial District, San Francisco, United States.

The Southern Pacific Building is an 11-story, 65-metre office building at One Market Plaza, completed in 1917 in the Italian Renaissance style with Roman brick and terra cotta. Its E-shaped plan runs 275 ft along Market Street, with 210-ft wings on Spear and Steuart Streets and elevators in the central arm. The lower facade has three round arches on paired columns, a clock, and the carved words "SOUTHERN PACIFIC COMPANY".

The building was constructed in 1917 as the headquarters for Southern Pacific Railroad and was the tallest steel-framed skyscraper in the western United States at completion. It shaped how tall buildings would be designed in the region afterward.

The building's name comes from the Southern Pacific Railroad, whose headquarters it became in 1917 after the move from the Flood Building. For many years a large sign with a gothic "S·P" topped the roof, marking the company's presence on the skyline. The carved band reading "SOUTHERN PACIFIC COMPANY" above the arches still names the original occupant.

The building fronts Market Street at the Embarcadero, with wings on Spear and Steuart Streets; the main entrance sits under the three arched portals on Market Street. It is part of One Market Plaza, so the lobby is shared with the Spear and Steuart towers. Look up from the sidewalk for the clock and the carved "SOUTHERN PACIFIC COMPANY" band.

The 1998–99 refurbishment removed two of the eight original passenger elevators and fitted custom-sized modern cabs into the other six shafts, which still run on the original guide rails. The elevators had already lost their operators in 1956, when automatic operation replaced them.