Nancy Jean Van de Vate (née Hayes; December 30, 1930 – July 29, 2023) was an American-born Austrian composer, violist and pianist. She also used the pseudonyms Helen Huntley and William Huntley. She is known for operas such as All Quiet on the Western Front, and orchestral music such as Chernobyl and Journeys, including concertos like the Kraków Concerto for percussion and orchestra.

Van de Vate taught at several universities in the United States and led composers' organizations such as the Southeastern Composers League and the International League of Women Composers. In 1985, she moved to Vienna, where she taught and founded a CD company for new orchestral music together with her husband.