Heinrich-Wolfgang Leopoldt (22 August 1927 – 28 July 2011) was a German mathematician, who worked on algebraic number theory. Leopoldt earned his Ph.D. in 1954 at the University of Hamburg under Helmut Hasse with the thesis Über Einheitengruppe und Klassenzahl reeller algebraischer Zahlkörper (On group of unity and class number of real algebraic number fields). As a postdoc, he was from 1956 to 1958 at the Institute for Advanced Study. In 1959, he obtained his habilitation degree at the University of Erlangen and was then at the University of Tübingen. From 1964, he was ordentlicher Professor at the University of Karlsruhe, where he was also Director of the Mathematics Institute.