Helen Turley is an American winemaker and wine consultant, known for bringing several Californian cult wines to the public awareness, and as the owner of a 20-acre (8.1 ha) boutique winery, Marcassin Vineyard.
Turley has also fostered other consultants, such as Mark Aubert, Philippe Melka, and Heidi Barrett. In addition to consulting for wineries such as Pahlmeyer, Bryant Family Vineyard, Colgin, Martinelli and Blankiet, until 1995, she was the winemaker for Turley Wine Cellars.
In 2001, the Roy Estate hired Turley and her husband, John Wetlaufer, to design their 17-acre (6.9 ha) Napa Valley vineyard and for Turley to serve as consulting winemaker. After making Roy Estate's 2003 & 2004 vintages, Turley canceled the arrangement in March 2005. The following September, the owners of Roy Estate filed a lawsuit against Turley and Wetlaufer alleging breach of contract. The lawsuit was eventually settled out of court in May 2006.