Willibald Jentschke (Vienna, Austria-Hungary, 6 December 1911 – Göttingen, Germany, 11 March 2002) was an Austrian-German experimental nuclear physicist. During World War II, he made contributions to the German nuclear energy project. After World War II, he emigrated to the United States to work at Wright-Patterson Air Force Base, in Ohio, for the Air Force Materiel Command.In 1950, he became a professor at the University of Illinois at Urbana–Champaign, where he became director of the Cyclotron Laboratory there in 1951.