John Hoyt (October 5, 1904 - September 15, 1991) was an American film, theatre, and television actor.

Before becoming an actor with Orson Welles's Mercury Theatre, the Yale graduate worked as a history instructor, acting teacher and even as a nightclub comedian. Under his birth name (John Hoysradt), Hoyt began his performing career in a nightclub act doing impressions of famous entertainers. His impersonation of Noël Coward was so remarkable that he was hired for the original cast of the Broadway comedy The Man Who Came to Dinner, in which he played Beverley Carlton, a role clearly based on Coward. Hoysradt began his movie career still using his birth name, but soon shortened it to Hoyt. He was known for playing villains in films, but also had a part (a non-pornographic one) in the softcore porn film Flesh Gordon. He also briefly appeared naked (shown only from the waist up) in X (The Man with X-Ray Eyes).

John had a number of memorable television roles including the grandfather on Gimme a Break!, a number of guest roles on Hogan's Heroes and the role of Dr. Philip Boyce on Star Trek's first pilot episode "The Cage". Another memorable role was as an evil Martian invader who tricks a busload of people and two policemen to take an unsafe bridge and fall to their deaths in episode 64 in the second season of the The Twilight Zone titled Will the Real Martian Please Stand Up. He appeared in one Shakespearean film, MGM's Julius Caesar, reprising the role of Decius Brutus (a.k.a Decimus Junius Brutus Albinus), which he had played in the famous 1937 Mercury Theatre production starring Orson Welles. He also appeared as KAOS agent Conrad Bunny in the Get Smart episode, "Our Man in Toyland". The last role of his acting career was an extended passionate monologue from the Gospel of Mark. In 1953, he portrayed Elijah in the biblical film Sins of Jezebel.

Hoyt, who died of prostate cancer in Santa Cruz, California, aged 86, was also in the film The Conqueror (1956). The movie was shot in Nevada while atomic bomb tests were being conducted nearby and is infamous for the number of cast members dying of cancer. He was cremated and his ashes were given to his wife in Soquel, California.

One of a long list of actors and crew who worked on the film Conqueror, The (1956) in 1956 that died from cancer some years later, including John Wayne (I), Susan Hayward (I), Agnes Moorehead, and Pedro Armendáriz, who was the first to contract cancer and committed suicide rather than face the horror of it.

Has one son and one grandson. Lance Polland, a Screenwriter and Director.

He had several guest appearances on the 1960s TV comedy show "Hogan's Heroes" (1965). He mostly played a high-ranking German Officer in the show, but never the same role twice.

In 1937 he performed (as John Hoysradt) at the prestigious Rainbow Room at Rockefeller Center. He headlined as 'the Master of Satire.'

He was the television spokesman in a series of Midas Muffler commercials in the 1960's.