Jack Warden (born John Warden Lebzelter Jr.; September 18, 1920 – July 19, 2006) was an American character actor of film and television. He was nominated for the Academy Award for Best Supporting Actor for Shampoo (1975) and Heaven Can Wait (1978). He received a BAFTA nomination for Shampoo, and won an Emmy for his performance in Brian's Song (1971).

Early life
Warden was born in Newark, New Jersey, the son of Laura M. (née Costello) and John Warden Lebzelter, who was an engineer and technician.

He was of Pennsylvania Dutch (German) and Irish ancestry. Raised in Louisville, Kentucky, he was expelled from high school for fighting and eventually fought as a professional boxer under the name Johnny Costello. He fought in 13 bouts as a welterweight, but earned little money.