John Agar was one of a promising group of leading men to emerge in the years after World War II. He never became the kind of star that he seemed destined to become in mainstream movies, but he did find a niche in genre films a decade later. Agar was the son of a Chicago meatpacker and never aspired to an acting career until fate took a hand in 1945, when he met Shirley Temple, the former child star and one of the most famous young actresses in Hollywood. In a whirlwind romance, the 17-year-old Temple married the 25-year-old Agar. His good looks made him seem a natural candidate for the screen and, in 1946, he was signed to a six-year contract by producer David O. Selznick. He never actually appeared in any of Selznick's movies, but his services were loaned out at a considerable profit to the producer, beginning in 1948 with his screen debut (opposite Temple) in John Ford's classic cavalry drama Fort Apache, starring John Wayne and Henry Fonda. His work in that movie led to a still larger role in Ford's She Wore a Yellow Ribbon, also starring Wayne. Those films were to mark the peak of Agar's mainstream film career, though John Wayne, who took a liking to the younger actor, saw to it that he had a major role in The Sands of Iwo Jima (1949), which was one of the most popular war movies of its era. In 1949, however, Temple divorced Agar and his career slowed considerably; apart from the film he did with Wayne, the most notable aspect of his career that year was his appearance in the anti-Communist potboiler I Married a Communist (aka The Woman on Pier 13). During the early '50s, he appeared in a series of low-budget programmers such as The Magic Carpet, one of Lucille Ball's last feature films prior to the actress becoming a television star, and played leads in second features, including the offbeat comedy The Rocket Man.
Agar seemed destined to follow in the same downward career path already blazed by such failed mid-'40s leading men as Sonny Tufts, when a film came along at Universal-International in 1955 that gave his career a second wind. The studio was preparing a sequel to its massively popular Creature From the Black Lagoon, directed by Jack Arnold, and needed a new leading man; Agar's performance in an independent film called The Golden Mistress had impressed the studio and he was signed to do the movie. Revenge of the Creature, directed by Arnold, was nearly as successful as its predecessor, and Agar had also come off well, playing a two-fisted scientist. He was cast as the lead in Arnold's next science fiction film, Tarantula, then in a Western, Star in the Dust, and then in The Mole People, another science fiction title. In between, he also slipped in a leading-man performance in Hugo Haas' crime drama Hold Back Tomorrow. He left Universal when the studio refused to give him roles in a wider range of movies, but his career move backfired, limiting him almost entirely to science fiction and Western movies for the next decade. In 1956, the same year that he did The Mole People, Agar made what was arguably the most interesting of all his 1950s films, Flesh and the Spur, directed by Edward L. Cahn for American International. The revenge Western, in which he played a dual role, wasn't seen much beyond the drive-in circuit, however, and was not widely shown on television; it is seldom mentioned in his biographies despite the high quality of the acting and writing. Agar was most visible over the next few years in horror and science fiction films, including Daughter of Dr. Jekyll, Attack of the Puppet People, The Brain From Planet Arous, Invisible Invaders, and Journey to the Seventh Planet. Every so often, he would also work in a mainstream feature such as Joe Butterfly or odd independent features like Lisette, but it was the science fiction films that he was most closely associated with and where he found an audience and a fandom. Coupled with his earlier movies for Universal, those films turned Agar into one of the most visible and popular leading men in science fiction cinema and a serious screen hero to millions of baby-boomer preteens and teenagers. The fact that his performances weren't bad -- and as in The Brain From Planet Arous, were so good they were scary -- also helped. It required a special level of talent to make these movies work and Agar was perfect in them, very convincing whether playing a man possessed by aliens invaders or a scientist trying to save the Earth. In 1962, he made Hand of Death, a film seemingly inspired in part by Robert Clarke's The Hideous Sun Demon, about a scientist transformed into a deadly monster, that has become well known in the field because of its sheer obscurity: The movie has dropped out of distribution and nobody seems to know who owns it or even who has materials on Hand of Death. By the time of its release, however, this kind of movie was rapidly losing its theatrical audience, as earlier examples from the genre (including Agar's own Universal titles) began showing up regularly on television. Hollywood stopped making them and roles dried up for the actor. He appeared in a series of movies for producer A.C. Lyles, including the Korean War drama The Young and the Brave and a pair of Westerns, Law of the Lawless and Johnny Reno, both notable for their casts of aging veteran actors, as well as in a few more science fiction films. In Arthur C. Pierce's Women of the Prehistoric Planet, Agar pulled a Dr. McCoy, playing the avuncular chief medical officer in the crew of a spaceship and also had starring roles in a pair of low-budget Larry Buchanan films for American International Pictures, Zontar, the Thing From Venus and Curse of the Swamp Creature. Amid all of these low-budget productions, however, Agar never ceased to try and keep his hand in mainstream entertainment -- there were television appearances that showed what he could do as a serious actor, perhaps most notably the 1959 Perry Mason episode "The Case of the Caretaker's Cat" (where he was billed as "John G. Agar," perhaps an effort to separate that work from his recent films) and tragic title role in the Branded episode "The Sheriff" (1967); and he always seemed to give 100% effort in those less classy oaters, horror outings, and space operas.
His career after that moved into the realm of supporting and character parts, including a small but key role in Roger Corman's first big-budget, big-studio film The St. Valentine's Day Massacre. He returned to working with John Wayne in three Westerns, The Undefeated, Chisum, and Big Jake, and turned up every so often in bit parts and supporting roles, sometimes in big-budget, high-profile films such as the 1976 remake of King Kong, but mostly he supported himself by selling insurance. In the 1990s, however, Agar was rediscovered by directors such as John Carpenter, who began using him in their movies and television productions, and he worked onscreen in small roles into the 21st century until his death in 2002.