Cornthwaite was born in Saint Helens, Oregon on April 28, 1917. His interest in acting began in his early teens, when he was forced to recite one line in a school play. He began his acting career in 1937, appearing in a college production of Twelfth Night, while attending Reed College in Portland, Oregon.[1]
Cornthwaite began his time in the US Army Air Force as a radio-gunner in B-25 aircraft as part of the 12th Medium Bombardment Group in 1942. He then served as a radio operator and superintendent of the watch with the 79th Fighter Group from 1943-1944. This was followed by serving as a writer and broadcaster with the Mediterranean Allied Air Forces from 1944 until 1945. In this position he performed Public Relations duties in Naples, Rome, Corsica, and other locations in the Mediterranean area. While on Corsica, Cornthwaite worked on his first film which was for the Free French Air Force. He acted as a writer and sound engineer recording Capitaine Eve Curie (daughter of Marie and Pierre Curie) of the Free French Air Force. He did the commentary in French and English. Cornthwaite also dubbed the voice of American Air Force General Ira Eaker, who did not speak French.[3]
In 1951, Cornthwaite was cast in Howard Hawks's production of The Thing from Another World. His character, Dr. Carrington, the unofficial leader of an Arctic polar expedition, observes the nearby crash of an unidentified flying object, and urges his military counterparts to communicate with the creature inside, even at the cost of their own lives. This performance eventually earned him entry into the "Science Fiction Hall of Fame" in 1993.
He remained primarily a stage actor throughout his career, and translated a number of plays from French to English. Balancing his theater work with "bill-paying" jobs, he appeared frequently on television, including a role as naturalistJohn James Audubon in three episodes of the Desilu Studios Production, The Adventures of Jim Bowie, starring Scott Forbes.
He appeared twice as Joe Brennan in the first Brian Keithtelevision series, Crusader, which aired on CBS in the middle 1950s. He appeared in five episodes of CBS's Perry Mason, including the role of murderer Herbert Dean in the series' third episode in 1957, "The Case of the Nervous Accomplice", and murderer Carl Bruner in the 1962 episode, "The Case of the Ancient Romeo".
