St. Helena is a city in Napa County, California, United States. Located in the North Bay region of the San Francisco Bay Area, the population was 5,438 at the 2020 census. St. Helena is a popular tourist destination, owing to its vineyards and culinary scene. The city is the center of St. Helena American Viticultural Area, which expands 9,060 acres of the Napa Valley with over 400 vineyards encompassing 6,800 acres of cultivation. St. Helena is the location of The Culinary Institute of America at Greystone and a campus of Napa Valley College.