100 First Plaza (also known as the Delta Dental Tower) is a 27-story, 136 m (446 ft) high-rise office building located at 100 First Street in the Financial District of San Francisco, California.

Construction of the building was completed in 1988.

It is the 35th-tallest building in the city.

[5] Skidmore, Owings & Merrill served as the design architects for the 100 First Plaza development that was designed with several setbacks, along with a grooved and faceted façade, and contains several rooftop curtain walls, and a notable 19 m (62 ft) spire.