| 100 First Plaza | |
| Alternate Names: | Andersen Tax Tower |
| Location: | 100 First Street San Francisco, California |
| Coordinates: | 37.7892°N -122.3975°W |
| Completion Date: | 1988 |
| Architect: | SOM |
| Owner: | Kilroy Realty Corporation |
| Floor Area: | 450200square feet |
| Floor Count: | 27 |
| References: | [1] |
| Building Type: | Commercial offices |
| Architectural Style: | Postmodern |
| Antenna Spire: | 136.25m (447.01feet) |
| Roof: | 116m (381feet) |
| Main Contractor: | Swinerton & Walberg |
| Pushpin Map: | United States San Francisco Central |
| Developer: | Barker Patrinely Group LLC |
| Management: | Kilroy Realty Corporation |
100 First Plaza (also known as the Delta Dental Tower) is a 27-story, 136m (446feet) 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.[2] 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 19m (62feet) spire.