Appeared with Steve McQueen in both McQueen's first major successful film (The Magnificent Seven (1960)) and in his last film (The Hunter (1980).
Appeared with Steve McQueen, Marilyn Monroe and Clark Gable in their final completed films: The Hunter (1980) and The Misfits (1961) (for both Monroe and Gable) respectively.
Graduated from The University of Texas at Austin - BA 1936.
Has a brother and two sisters, all of whom became teachers.
He has had two hip replacements and has arthritis in his back.
He has three grandsons.
He is one of only 9 actors to have played "Special Guest Villains" in "Batman" (1966) who are still alive, the others being Malachi Throne, Julie Newmar, John Astin, Joan Collins, Glynis Johns, Barbara Rush, Dina Merrill and Zsa Zsa Gabor.
He served for five years in the Army's Medical Administrative Corps during World War II, eventually attaining the rank of captain.
He, his wife Anne Jackson and their daughter, Roberta Wallach, have all made guest appearances in "Law & Order" (1990) in different episodes.
In 1966, he starred in The Good, the Bad and the Ugly (1966) ("The Good, The Bad, and the Ugly") with Clint Eastwood. Thirty-seven years later, Eastwood directed Wallach in Mystic River (2003).
In an interview on "Fresh Air" (on station WHYY in Philadephia, Pennsylvania), he explained to Terry Gross that he learned to ride horses at the University of Texas: He took care of the polo ponies. During the filming of the The Magnificent Seven (1960), each morning he would ride a few hours with his gang.
In the "Murder, She Wrote" (1984) episode "A Good Year for Murder", he played a dying man, Salatore Gambini, who committed a murder because he had nothing to lose. In the "Law & Order" (1990) episode "The Working Stiff", he played a character, Simon Vilanis, who was suspected of committing a murder for the same reason although he ultimately proved to be innocent.
Is blind in the left eye due to a stroke.
One of his best known roles is the lead bandit Calvera in The Magnificent Seven (1960). Although his character is eventually defeated in the film, he has outlived six of the seven stars, as Robert Vaughn is the only one who is still alive as of 2009, despite the fact that he is older than all of them.
One of his fellow students at Parsons New School for Social Research in New York was Marlon Brando.
One of three actors to play the character of Mr. Freeze on "Batman" (1966). (The other two were George Sanders and Otto Preminger). He once said that he has received more fan mail for that role than for any other role he has ever done.
There was no official theater department at the University of Texas when he attended, so he joined a student organization called The Curtain Club to put on plays. One of the other students involved was future Governor of Texas John Connally.