Walter Gordon (3.08.1893-24.12.1939) was a German theoretical physicist. He was born in Apolda. He graduated from the University of Berlin (1921). He worked at the universities of Berlin, Manchester and Hamburg and at the Kaiser Wilhelm Institute for Chemistry. In 1933 he moved to Sweden, where he worked at the Institute of Mathematical Physics of Stockholm University. His work concerned atomic physics and quantum mechanics. In 1926 he formulated (independently of O. Klein and V. A. Fock) a relativistically invariant quantum equation for particles of zero spin (the Klein — Fock — Gordon equation). In 1928, starting from Dirac's theory of the electron, he derived the fine-structure formula.