Santa Rosa (Spanish for "Saint Rose") is a city and the county seat of Sonoma County, in the North Bay region of the Bay Area in California. Its estimated 2019 population was 178,127. It is the largest city in California's Wine Country and Redwood Coast. It is the fifth most populous city in the Bay Area after San Jose, San Francisco, Oakland, and Fremont; and the 25th most populous city in California.