John Arthur Rubinstein (born December 8, 1946) is an American film, Broadway, and television actor, a composer of film and theatre music, and a director in theatre and television.

John was born in Los Angeles, California, the son of Polish parents. His mother, Aniela (née Młynarska), a dancer and writer, was a Roman Catholic native of Warsaw, the daughter of conductor Emil Młynarski. His father was Polish-born Jewish concert pianist Arthur Rubinstein. He attended Staples High School in Westport, Connecticut. He graduated from the University of California, Los Angeles in 1967.