650 California Street, also known as the Hartford Building, is a 34-story, 142 m office tower on the northwestern edge of San Francisco's Financial District. The tower is located on California Street on the edge of Chinatown, and not far from 555 California Street. 650 California is visible from every direction except from the southeast, where the Financial District skyscrapers block the view.

California Street is a major thoroughfare in San Francisco, California. It is one of the longest streets in San Francisco, and includes a number of important landmarks. It runs in an approximately straight 5.2 mi (8.4 km) east–west line from the Financial District to Lincoln Park in the far northwest corner of the city.