Napa County is a county located north of San Pablo Bay in the U.S. state of California. It is officially one of the nine San Francisco Bay Area counties, and one of four North Bay counties. The county is coterminous with the Napa, California, Metropolitan Statistical Area. As of the 2010 census the population is 136,484. The county seat is Napa. Napa County was one of the original counties of California, created in 1850 at the time of statehood. Parts of the county's territory were given to Lake County in 1861.
Napa County, once the producer of many different crops, is known today for its regional wine industry, rising to the first rank of wine regions with France by local wineries Stag's Leap Wine Cellars and Chateau Montelena winning the "Judgment of Paris" in 1976.