Knights Valley AVA is an American Viticultural Area in Sonoma County, California. One of Sonoma County's original five American Viticultural Areas (AVAs), Knights Valley AVA was formally designated an American Viticultural Area on October 21, 1983. Knights Valley AVA includes approximately 37,000 acres (150 km²). Over 30 growers maintain the 2,000 acres (8 km²) planted to wine grape vineyards. The easternmost designated Sonoma County wine region, Knights Valley AVA has the warmest climate in the county. The valley lies between the Alexander Valley AVA and Chalk Hill AVA wine regions to the west and the Mayacamas Mountains to the east.