Karras was born on July 15, 1935 in Gary, Indiana. He studied at the University of Chicago. Karras was married to Joan Jurgensen from 1958 until they divorced in 1975. Then he was married to Susan Clark from 1980 until his death in 2012. With Jurgensen, he has five children. Then with Clark he has one child. Karras died on October 10, 2012 in Los Angeles, California from kidney failure, aged 77.