The Commercial Union Assurance Building is a 94 m (308 ft), 16-story office building located in the Financial District of San Francisco, California.

The building was completed in 1921 and is the same height of the San Francisco City Hall.

[3] The much taller 555 California Street is to the west of this Renaissance Revival styled building.

Floors 9 and 10 are now flexible coworking spaces[4]