Born in Brooklyn, New York as Sidney Meltzer, he was the son of Isidor Meltzer, a Yiddish theater comedian, and the brother of screenwriter Lewis Meltzer. He made his stage debut in a 1939 touring production of See My Lawyer and in 1941 was cast as Fingers in Shadow of the Thin Man. During World War II Melton entertained American soldiers overseas and met screenwriter Aubrey Wisberg, who arranged for him to have a part in his The Treasure of Monte Cristo for Robert Lippert. This was his first film after signing his first Hollywood contract with Lippert Pictures in 1949. The studio churned out low-budget films, most of them made in less than a week, and he was the comic relief in dozens of them, including Monte Cristo, Mask of the Dragon and Lost Continent.[citation needed] Other movies included On the Town, The Geisha Boy, The Tunnel of Love, and Blondie Goes to College. He appeared in two Lippert Pictures, Lost Continent and Radar Secret Service, later featured on Mystery Science Theater 3000, whose hosts gave Melton the nickname “Monkey Boy” due to his comedy relief antics. He played Captain Midnight’s sidekick, Ichabod “Icky” Mudd, in Captain Midnight, an early 1950s Saturday-morning children’s show. Until the end of his life, old fans would greet him on the street with his signature introductory gag line, “Mudd with two D’s.” Melton appeared three times as Harry Cooper in the 1955–56 sitcom It’s Always Jan. In the late 1950s, he played several small roles in the popular Desilu show The Lucy-Desi Comedy Hour as a construction worker who comes into the room through the window to ask for Milton Berle’s autograph for his children. He starred in another episode in which he plays a bellboy for a hotel in Nome, Alaska that Lucy and the gang are staying at.

His television credits included Captain Midnight, Dragnet, The Silent Service, and M Squad. He appeared in four episodes of the final two seasons of Gomer Pyle, U.S.M.C. as “Friendly Freddy”, an unsuccessful con-artist who bilks Gomer and Sgt. Carter, among others, but always gets caught, sometimes several times in the same episode. He usually blames an unscrupulous supplier and vows to never use him again, then seems to make up for it by providing a refund or replacement merchandise, which inevitably turns out to be another con. He had guest roles on Adventures of Superman, I Dream of Jeannie and The Dick Van Dyke Show; in the last he played deli owner Bert Monker, who is in love with Sally Rogers (played by Rose Marie). Melton was married once, in the 1940s, but the marriage was annulled. “After that,” said his brother-in-law, David Lawrence, “he kept dogs, mainly wire-haired terriers.” In 2005, he attended Eddie Albert’s funeral along with Green Acres co-stars Mary Grace Canfield and Frank Cady. Melton died from pneumonia on November 2, 2011, aged 94. He was interred at Mount Sinai Memorial Park in Los Angeles, California.