Oleg Liagachev was born in Leningrad in 1939. Between 1956 and 1958 he studied physics at Leningrad State University. He received his formal education in art from 1960 to 1966 at the Leningrad Academy of Arts. In 1964 he took part in the famous Hermitage exhibit «Artists-workers of an economic part» together with Chemiakin. He came to the Saint Petersburg Group in 1967 and joined them in their call for artistic freedom. He worked at the Hermitage until 1975 and during this time he began to integrate into his work elements of religious art of the Middle Ages. In 1975 he took part in the exhibit of nonofficial art held at the Nevsky Palace of Culture.
After years of conflict with the authorities, Liagachev emigrated in 1976 to France. He lives and works in Paris, and regularly participates in the activities of the St. Petersburg alternative art movement.