Walter Friedrich Karl Weizel (1 August 1901 in Lauterecken – 6 August 1982) was a German theoretical physicist and politician. As a result of his opposition to National Socialism in Germany, he was forced into early retirement for a short duration in 1933. He was professor of theoretical physics at the Institut für Theoretische Physik, University of Bonn, from 1936 to 1969. After World War II, he helped to establish the Jülich Research Center, and he was a state representative of the Social Democratic Party of Germany.