Born in 1939 in the village of Lermontovka, Khabarovsk Krai.
From 1963 to 1968 he studied at the Sverdlovsk art College in painting and pedagogical Department (supervisors: E. P. Roshchina, G. P. guys). Thesis - "Innovators".
In 1972 he organized in Asbest city Children's art school, was its first Director (1972 to 1978).
Since 1968 - the participant of city exhibitions, in 1990 and 1995 held a personal exhibition of the artist.
Works O. Mamaev are stored in the Museum. Avvakumov in the town of Asbestos.