Kiyoshi Oka (岡 潔, Oka Kiyoshi, April 19, 1901 – March 1, 1978) was a Japanese mathematician who did fundamental work in the theory of several complex variables.
Oka was born in Osaka. He went to Kyoto Imperial University in 1919, turning to mathematics in 1923 and graduating in 1924.
He was in Paris for three years from 1929, returning to Hiroshima University. He published solutions to the first and second Cousin problems, and work on domains of holomorphy, in the period 1936–1940. He received his Doctor of Science degree from Kyoto Imperial University in 1940. These were later taken up by Henri Cartan and his school, playing a basic role in the development of sheaf theory.
Oka, Kiyoshi (1961). Sur les fonctions analytiques de plusieurs variables (in French). Tokyo, Japan: Iwanami Shoten. p. 234. - Includes bibliographical references.
Oka, Kiyoshi (1983). Sur les fonctions analytiques de plusieurs variables (in French) (Nouv. ed. augmentee. ed.). Tokyo, Japan: Iwanami. p. 246.