Steve Railsback (born November 16, 1945, in Dallas, Texas) is an American theatre, film, and television actor. He is best known for his performances in the films The Stunt Man and Lifeforce, and his portrayal of Charles Manson in the 1976 television mini-series Helter Skelter.

Railsback was a student of Lee Strasberg and the Actors Studio and in the late 1960s and early 1970s spent 10 years working in theatre in New York City. He once said that he found Strasberg extremely difficult to work with.