Fairfield is a city located in the northeastern portion of the San Francisco Bay Area in Northern California, USA (See East Bay and North Bay). It is approximately 38 miles (61 km) from both the city of San Francisco and the city of Sacramento, approximately 34 miles (55 km) from Oakland, less than 18 miles (29 km) from Napa Valley, 15 miles from the Carquinez Bridge, and 13 miles from the Benicia Bridge. Fairfield was founded in 1859 by clippership captain Robert H. Waterman, and named after his former hometown of Fairfield, Connecticut. It is the home of Travis Air Force Base and the Jelly Belly jelly bean factory. With a population of 105,321 at the 2010 census, it is slightly smaller in population than Vallejo, which is the Bay Area's ninth-largest city. It shares a border with its sister city, Suisun City. Other nearby cities include Vacaville, Benicia, and Napa. Fairfield is the county seat of Solano County.
According to the United States Census Bureau, the city has a total area of 37.6 square miles (97.5 km²), of which, 37.4 square miles (96.8 km²) of it is land and 0.2 square miles (0.6 km²) of it is water. The total area is 0.65% water.
The city is located within the California Coastal Ranges of the San Francisco Bay Area. The city is centered directly north of the Suisun Bay and northeast of the San Pablo Bay. Much of the Suisun Bay contains the Suisun Marsh, the largest saltwater marsh on the west coast of the United States. The Sacramento Valley lies east of Fairfield.