(born 31 May 1907, Colchester, England; d. 24 October 1979 Southampton) was a British scientist of German descent.
He was the son of Friedrich Wilhelm Hermann Jahn and Marion May Curtiss.
Jahn received his Bachelor of Science degree in chemistry at University College, London in 1928.
He received his PhD on 14 February 1935 under the supervision of Werner Heisenberg at the University of Leipzig.
He published scientific papers on quantum mechanics and group theory.