Paso Robles is the third American Viticultural Area (AVA) located in San Luis Obispo (SLO) County, California. It was established by the Bureau of Alcohol, Tobacco and Firearms (ATF), Treasury on November 3, 1983 based on a petition submitted by Martin-Brothers Winery. The area encompasses 609,673 acres (953 sq mi) with approximately 18,500 acres (7,487 ha) cultivated with wine grapes known for their heritage varietal Zinfandel, Cabernet Sauvignon, and Rhône-style wines.

An American Viticultural Area (AVA) is a designated wine grape-growing region in the United States, providing an official appellation for the mutual benefit of wineries and consumers. Winemakers frequently want their consumers to know about the geographic pedigree of their wines, as wines from a particular area can possess distinctive characteristics. Consumers often seek out wines from specific AVAs, and certain wines of particular pedigrees can claim premium prices and loyal customers. If a wine is labeled with an AVA, at least 85% of the grapes that make up the wine must have been grown in the AVA, and the wine must be fully finished within the state where the AVA is located.