He passed away of respiratory failure at his Sherman Oaks, California home on Tuesday (27Mar12), according to the Associated Press.
Stevens was born in Pennsylvania and enrolled as a pilot in the U.S. Army Air Force at the age of 17. He later moved to New York to pursue a career in entertainment, eventually training at The Actor's Studio.
He landed his first part in The Frogmen in 1951, and went on to star in The Barefoot Contessa with Humphrey Bogart, before taking on his most memorable role as 'Doc' Ostrow in the science fiction classic Forbidden Planet.
The actor also made a number of television guest appearances - his credits include ER, The Twilight Zone, Star Trek, I Spy, The Outer Limits, M*A*S*H, and The Mod Squad.