Fairfield is a city in and the county seat of Solano County, California, in the North Bay sub-region of the San Francisco Bay Area. It is generally considered the midpoint between the cities of San Francisco and Sacramento, approximately 40 miles (64 km) from the city center of both cities, approximately 40 miles (64 km) from the city center of Oakland, less than 19 miles (31 km) from Napa Valley, 16 miles (26 km) from the Carquinez Bridge, and 14 miles (23 km) from the Benicia Bridge. Fairfield was founded in 1856 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 headquarters of Jelly Belly. With a population of 108,321 at the 2010 census, it is slightly smaller in population than Vallejo. Other nearby cities include Suisun City, Vacaville, Rio Vista, Benicia, and Napa.
According to the United States Census Bureau, the city has a total area of 37.6 square miles (97 km2), of which, 34.4 square miles (89 km2) of it is land and 3.2 square miles (8.3 km2) of it is water. The total area is 5.65% water.
The city is located within the California Coastal Ranges. The city is centered directly north of the Suisun Bay and northeast of the San Pablo Bay.