Concannon Vineyard is the second-largest winery in California's Livermore Valley, producing about 30,000 cases per year. It is well known for its Petite Sirah, and Concannon was the first winery to bottle the grape as a varietal wine in 1961. Prior to 1961, small sirah grapes were produced worldwide as blended wines. It also produces a variety of other varieties of wine, including Chardonnay and Cabernet Sauvingnon. Concannon is the owner of The Wine Company.

The story of the Concannon began in 1865 when James, then an 18-year-old boy, bravely set out from the rocky coast of the Irish Aran Islands to pursue a chance in America.

Even at such a young age, Concannon recognized that the terroir of the Livermore Valley in the central coast of California was remarkably similar to the first Bordeaux vineyards. In 1883, therefore, he founded Concannon Vineyard with a range of high-quality vines which he imported directly from Bordeaux, including the renowned Château Margaux and Château d'Yquem.

Concannon worked closely with early California wine-growing leaders Charles and Clarence Wetmore to decide whether California could be a good wine-growing area. Their efforts paid off at the 1889 International Paris Exhibition, when the Livermore Valley became the first American Wine Region to win international gold medals, including the Grand Prix.

Captain Joe Concannon (son of James) kept Concannon Vineyard running continuously during the scourge of Prohibition by producing and selling sacramental wine. This avoided the destruction of the 1893 Château Margaux Cabernet Sauvignon root stock and other historic Bordeaux vineyards.

In the early 1930s, Captain Joe was one of the first in the world to bottle Cabernet Sauvignon as a single varietal wine. In the 1950s, he employed one of the first professionally trained female winemakers, Katherine Vajda, to serve as Concannon's leading winemaker.

In 1965, grandson Jim worked with UC Davis in the collection of cuttings from one of Concannon's ancient Margaux vines. These dynamic, high-quality cuttings have become known as Concannon Cabernet Clones 7, 8, and 11. Today, an estimated 80% of California's Cabernet Sauvignon is planted with Concannon Clones.

In 2008, John Concannon took over the leadership of his father as a fourth generation winemaker. In 2009, Concannon Vineyard was one of the first wineries to be certified sustainable in California. The estate winery also completed a 10-year revitalization project during this period.