John Studebaker "Jack" Hardy (November 23, 1947 – March 11, 2011) was an American lyrical singer-songwriter and playwright based in Greenwich Village, who was influential as a writer, performer, and mentor in the North American and European folk music scenes for decades. He was cited as a major influence by Suzanne Vega, John Gorka, and many others who emerged from that scene in the 1970s, 1980s, and 1990s. Hardy was the author of hundreds of songs, and toured tirelessly for almost forty years. He was also the founding editor of Fast Folk Musical Magazine, a periodical famous within music circles for twenty years that shipped with a full album (and later, compact disc) in each issue, whose entire catalog is now part of the Smithsonian Folkways collection.

Hardy died on the morning of March 11, 2011 in Manhattan. He was 63. The cause was complications of lung cancer.