William Joseph Chaminade or Guillaume-Joseph Chaminade, now called by his liturgical title of Blessed Chaminade (April 8, 1761 – January 22, 1850), was a French Roman Catholic priest who survived persecution during the French Revolution. He founded the Society of Mary, also called the Marianists, in 1817. The Marianist Family's other three branches—the married and single men and women of the Marianist Lay Communities, the consecrated laywomen of the Alliance Mariale, and the nuns known as Daughters of Mary Immaculate—also look to Chaminade as a founder or inspiration. Beatified by Pope John Paul II on September 3, 2000, Blessed Chaminade's feast day is celebrated on January 22.