Tom Hagen — The Godfather (1972)

Duvall's breakthrough role: the quiet, methodical consigliere to the Corleone family. Tom Hagen is the moral anchor of the film — the man who keeps the family's business running while chaos surrounds him. Duvall plays him with coiled restraint, never competing for attention with Brando or Pacino, yet leaving an indelible mark on every scene. The Academy nominated him for Best Supporting Actor. Often overshadowed, it was the role that made Hollywood finally notice Robert Duvall.