Oleg Nikolayevich Yefremov was born in Moscow in 1927. He spent his childhood and adolescence in the well-known Arbat yards and lanes, living in a huge communal flat in the very heart of Moscow.

In the spring of 1945, having succeeded in an enormous competition, the eighteen-year-old Oleg became the student of the Actor's Faculty of the School-Studio of MKhAT. As a freshman cherishing nearly a religious feeling to Stanislavsky’s teaching, together with several fellow students he swore a loyalty oath to his idol and sealed it with his own blood.

Upon graduation of the MKhAT School-Studio in 1949 he was invited to the company of the Central Children's Theatre where he played more than 20 roles within a short period. There he also debuted as the stage director with the vaudeville Dimka the Invisible (1955).

At the same time the actor started to teach at MKhAT School-Studio. In 1956, having gathered around himself students and graduates of the School-Studio, both his coevals and pupils (Galina Volchek, Liliya Tolmacheva, Evgeni Evstigneev, Igor Kvasha, Oleg Tabakov, and Viktor Sergachyov among them), Oleg Yefremov organized the Studio of Young Actors (subsequently — the Moscow famous Sovremennik Theatre) and became its art director.

Oleg Yefremov’s student's diary harbours an amazingly courageous and impudent record: "I will be the chief stage director of MKhAT!" That is very characteristic of Oleg Yefremov: he took the stage to be the head, the leader.

Oleg Yefremov debuted as a film actor in the melodrama The First Echelon (Pervyy eshelon) in 1955. Since then he was regularly into filming, and his every appearance on screen turned to be a real event for millions of spectators. The actor of rare integrity, naughty temperament and rich imagination, Oleg Yefremov was able to elaborate a role in tiny detail, thus creating a complete full-fledged portrayal. In the course of time the actor's palette was enriched with a variety of shades: from soft or at times bitter irony and gentle lyricism to high tragedy.

Yefremov’s characters were not just appealing. Within a few minutes of screen time they became soul mates for quite different people. They gave hope, and made life brighter and longer. Such was his tankman Ivanov from the military film novel The Quick and the Dead (Zhivye i myortvye) (1964), as well as Sasha the taxi driver radiating fantastic charm in the splendid melodrama Three Poplars in Plyushcikha (Tri topolya na Plyushchikhe) (1967). Such was the infinitely touching Feodor, a born artist in the film Shine, Shine, My Star (Gori, gori, moya zvezda) (1969) …

Oleg Yemremov’s innumerable admirers were enchanted with his exquisite comedy gift in the role of stoic doctor Aybolit (Aybolit-66 (1966)), as well as his absurdly earnest investigator Podberezovikov in Watch Out for the Automobile (Beregis avtomobilya) (1966) …

His half-minute role in the film The Girl and the Bugler (Zvonyat, otkroyte dver) (1965) indicates how great his talent was. Yefremov’s character, once a fervent pioneer, is today a hopeless old drunkard. Opening the door of the communal flat, he does not say a word. But his dispirited aloof look embodies an entire generation. At first the film viewers don’t recognize Yefremov in this person. Having recognized him, they burst out laughing – so pathetic and absurd his character is. The unexpected appearance of Yefremov lasts for all half a minute only, but the impression stays long.

In 1970 Oleg Yefremov accepted the invitation of the senior generation of MKhAT actors and became its chief director (just as he had wished in his diary). For thirty years of work in the Art Theatre he staged more than 40 plays and acted in 14 of them.

Oleg Yefremov got married some times. His son — actor Mikhail Yefremov (born 1963) – was born from his marriage to actress Alla Pokrovskaya.

Oleg Nikolayevich Yefremov died at the age of 72 in his flat in Moscow at the end of spring 2000. He was laid to rest at Novodevichy Cemetery in Moscow.