Walter Thiel (7 March 1949 in Treysa, Hesse – 23 August 2019)[2] was a German theoretical chemist.

[1] He was the president of the World Association of Theoretical and Computational Chemists (WATOC) from 2011.

[3] Thiel studied chemistry at the University of Marburg (West Germany) from 1966 to 1971, where he subsequently obtained his doctorate with Armin Schweig in 1973.

[2][1] Since 1999, he was a director at the Max Planck Institute for Coal Research in Mülheim an der Ruhr (Germany) and an honorary professor at the neighboring University of Düsseldorf (Germany) since 2001.

[1] His group was involved in the development of new theoretical methods, in particular for the treatment of large molecules, and applied theoretical calculations to concrete chemical problems, usually in close collaboration with experimentalists.