At the request of General Mariano Guadalupe Vallejo, Solano county was named for Chief Solano of the Suisun people, a Native American tribe of the region and Vallejo's close ally.
Solano County comprises the Vallejo–Fairfield, CA Metropolitan Statistical Area and is the northeastern county in the nine-county San Francisco Bay Area region. A portion of the South Campus at UC Davis is in Solano County.