The Godfather and The Godfather, Part II: Marlon Brando and Robert DeNiro

Okay, we're bending the rules here a bit to cover the same iconic role that stretches across two iconic pictures. Marlon Brando won the Best Actor Oscar in 1973 for his portrayal of Don Vito Corleone, and just one year later, Robert DeNiro won the Best Supporting Actor Oscar for portraying a younger version of Vito in The Godfather, Part II (a film that is geniously both prequel and sequel). This marked not just the only time that two different actors won an Oscar for playing the same role, but also the only time that both said actors didn't show up for their respective Oscar ceremonies.