Oleg Stefan né Oleg Stepanovich Shtefanko (Russian: Оле́г Степа́нович Штефанко́; born September 7, 1959) is a Soviet and Russian actor who gained popularity in Russia after moving there to study acting. He later established himself as an American film actor following his emigration to the United States.

He studied acting in Moscow and graduated in 1980, subsequently becoming a member of the Moscow Maly Theater. He starred in several Soviet films until the Soviet Union's collapse in 1991.

In 1992, Oleg Stefan emigrated to the United States. Since then, he has appeared in several popular television series, including Frasier and JAG. He also had a role in Robert De Niro's The Good Shepherd opposite Matt Damon.

After 2003, Oleg Stefan returned to the Russian entertainment industry, taking on leading and supporting roles in several Moscow-produced films.

In 2005, he received a nomination for the Gold Nymph Award as Best Actor at the 45th International Festival of Television Films in Monte Carlo.