Seiji Kaya (born 21.12.1898) is a Japanese physicist and a member of the Japan Academy (1961). He graduated from Tohoku University (1923). In 1931-43 he was professor at Hokkaido University (Sapporo), in 1941 —48 at the Tokyo Institute of Technology, and from 1943 at the University of Tokyo (president in 1958 — 60).
His research was in the field of the physics of metals and ferromagnetism. A foreign member of the USSR Academy of Sciences (1958).