Guest appearances
On Gunsmoke, in a 1957 episode titled "Bureaucrat", Hoyt played the part of Rex Propter, a government agent sent to Dodge City, Kansas, to determine why the town had such a bad reputation for gun violence. He made five guest appearances on Perry Mason, including in the role of defendant Joseph Harrison in the 1958 episode "The Case of the Prodigal Parent", as C. Philip Reynolds in the 1958 episode "The Case of the Curious Bride", as the title character and defendant William Harper Caine in the 1961 episode "The Case of the Resolute Reformer", and as Darwin Norland in the 1963 episode "The Case of the Libelous Locket". In the 1964 episode "The Case of the Wednesday Woman", Hoyt played Thomas Webber, part owner of a jewelry business. He guest-starred, as well, on Crossroads.
Hoyt was cast in 1958 as rancher Clete Barron in the episode "Trouble in Paradise Valley" of Frontier Doctor. Also in 1958, Hoyt was cast as a clothier in Leave It To Beaver's "Wally's New Suit" episode. In 1958 and 1959, he performed in two episodes of Richard Diamond, Private Detective, appearing as Burnison in "The George Dale Case" and as Harding, Sr. in "Murder at the Mansion". Later in 1959, on Laramie, Hoyt portrayed mentally troubled military officer Colonel Brandon in "The General Must Die". The same year, he was cast as Antoine Rigaud in the episode "About Roger Mowbray" on Riverboat.
In 1959, Hoyt was cast as John Cavanagh in "The Mourning Cloak", an episode of the crime drama Bourbon Street Beat. About this time, he guest-starred on The Alaskans and Pony Express. Also in 1959, Hoyt was cast in an episode ("Three Legged Terror") of The Rifleman, playing the character Gus Fremont, the cruel uncle of Johnny Clover (Dennis Hopper). He returned to The Rifleman in late 1960 as Civil War veteran Captain Josiah Perry, a man deranged by grief over the loss of his son, in the episode "The Martinet". In 1960 and 1961, he appeared in the episodes "Burnett's Woman" and "The Salvation of Killer McFadden" of The Roaring 20's. Hoyt also appeared on The Untouchables in the 1960 episode "The Big Squeeze".
Hoyt guest-starred on at least three sitcoms: Bringing Up Buddy, Hogan's Heroes, and Petticoat Junction (in the 1966 episode "Hooterville Valley Project", as Mr. Fletcher). He was cast as Dr. Philip Boyce in the pilot episode of Star Trek ("The Cage"), and he appeared twice during the second season of The Twilight Zone as both the titular character in the classic episode "Will the Real Martian Please Stand Up?" and as Dr. Loren in the episode "The Lateness of the Hour". He appeared as KAOS agent Conrad Bunny in "Our Man in Toyland" on Get Smart, as General Beeker in "Hail to the Chief" on Voyage to the Bottom of the Sea, and as Dr. Mendoza in "I Was a Teenage Monster" on The Monkees. He guest-starred as Colonel Hollis in "Military School" on The Beverly Hillbillies. He appeared twice in the first season of The Munsters, in episodes 12 ("Sleeping Cutie") and 35 ("Herman's Happy Valley").
In 1964, Hoyt appeared in three episodes of The Outer Limits, most notably "The Bellero Shield". He played the role of an extraterrestrial with large eyes who says, "In all the universes, in all the unities beyond the universes, all who have eyes have eyes that speak." Less than two weeks after this episode's broadcast, alleged alien abductees Betty and Barney Hill provided a description of their alien abductors. Skeptic Martin Kottmeyer notes that the description is notably similar to Hoyt's appearance as the extraterrestrial on the show.
He was also a guest player in "The 14-Karat Gold Trombone" and "The Interview" episodes of The George Burns and Gracie Allen Show. Because of his stern demeanor, the writers had him play opposite to the befuddled way strangers usually reacted to Gracie Allen's convoluted behavior. In the teleplay of "The Interview", Hoyt simply would not tolerate Gracie's antics and immediately removed himself from the room—twice.
He incarnated Bertrand Russell and Voltaire in episodes of Steve Allen's PBS series Meeting of Minds in the late 1970s. He appeared as Sire Domra in episode 21 "Baltar's Escape" of Battlestar Galactica.
