Oleg Shtefanko, after graduating from secondary school in 1976, entered the Shchepkin Theatre School in Moscow. As a second-year student he played two roles on the stage of the Maly Theatre. In 1979 his television and film career began. After graduating from the theatre school in 1980 he was accepted into the troupe of the Academic Maly Theatre of the USSR, where he performed alongside such actors as Smoktunovsky, Tsaryov, Ilyinsky, Zharov, the Solomin brothers, and Martsevich. He worked in radio, television, and film. With his solo concert program he toured many cities of the Soviet Union. In 1985-1986 he served in the ranks of the USSR Armed Forces in the Moscow region in the engineering troops. On the stage of the Maly Theatre he played in more than 20 plays. Some of them: "Long Day's Journey into Night", "Agony", "Cyrano de Bergerac", "The Shore". In early 1992 Shtefanko emigrated to the USA. Living in New York, he mastered new professions: waiter, taxi driver, bartender, car dealer; security guard, kickboxer; he sold insurance policies. At the same time he worked in the modeling business and theatre, and performed on the stage of the "Theater of New York City". In New York Oleg appeared in his first American film.

In 1994 he moved to Los Angeles and worked in television and film. He was accepted into two American acting guilds: SAG - the Screen Actors Guild, and AFTRA - the American Federation of Television and Radio Artists. In Los Angeles he continued his education at the "L.A. Actors Circle Theater School". After obtaining American citizenship, he changed his surname to Oleg Stefan. Under this name he appeared in 14 films in Hollywood, working with such actors as Robert De Niro, Michael York, Gene Hackman, Sigourney Weaver, Jude Law, James Belushi, Leonardo DiCaprio, Matt Damon, Alec Baldwin, Vincent Perez, Julia Roberts, Clive Owen, Paul Giamatti, Tom Wilkinson, Denis O'Hare and others. Later he returned to Russia, where he continued to act. Oleg Shtefanko gained wide fame for the role of Leonid Zubov in the series "Lesnik". In total Shtefanko has 76 film and television credits, in 54 of which he played the lead roles. Personal life: First wife - Larisa Shtefanko, Daughter - Kristina, Son - John (Ivan), born in the late 1990s. It was decided to name him Ivan. But after some time his name was changed to John, as it sounds better to Americans. Second wife - Anna Shtefanko.