Sonoma is a city in Sonoma County, California, United States, located in the North Bay region of the San Francisco Bay Area. Sonoma is one …Sonoma is a city in Sonoma County, California, United States, located in the North Bay region of the San Francisco Bay Area. Sonoma is one of the principal cities of California's Wine Country and the center of the Sonoma Valley AVA. Sonoma's population was 10,739 as of the 2020 census, while the Sonoma urban area had a population of 32,679. Sonoma is a popular tourist destination, owing to its Californian wineries, noted events like the Sonoma International Film Festival, and its historic center.