Elam was born in Miami in Gila County in south central Arizona, to Millard Elam and Alice Amelia Kirby. His mother died in 1922 when Jack was two years old. By 1930, he was living with his father, older sister Mildred, and their stepmother, Flossie Varney Elam. He grew up picking cotton and lost the sight in his left eye during a boyhood accident when he was stabbed with a pencil at a Boy Scout meeting. He was a student at both Miami High School in Gila County and Phoenix Union High School in Maricopa County, graduating from there in the late 1930s. Elam attended Santa Monica Junior College in California. After that, he worked as a bookkeeper at the Bank of America in Los Angeles and as an auditor for the Standard Oil Company. In World War II, he served two years in the Navy and subsequently became an independent accountant in Hollywood; one of his clients was movie mogul Samuel Goldwyn. At one time, he was the manager of the Bel Air Hotel in Los Angeles. In 1949, Elam made his debut in She Shoulda Said No!, an exploitation film where a chorus girl’s marijuana smoking ruins her career and drives her brother to suicide. He appeared mostly in westerns and gangster films playing villains. Elam made multiple guest star appearances in many popular Western television series in the 1950s and 1960s, including “Gunsmoke”, “The Rifleman”, “Lawman (TV series)”, “Bonanza”, “Cheyenne”, “Have Gun Will Travel”, “Zorro”, “The Lone Ranger” and “Rawhide”. In 1961, Elam played a slightly crazed character in an episode of The Twilight Zone entitled “Will the Real Martian Please Stand Up?.” In April of 1966 Jack Elam co-starred with Clint Walker in the western “The Night of The Grizzly”.

In 1963, Elam got a rare chance to play the good guy, Deputy U.S. Marshal and reformed gunfighter J. D. Smith in the ABC/Warner Brothers series, The Dakotas, a television western that ran for only nineteen episodes. He played George Taggart, a gunslinger-turned-marshal in the NBC/WB western series, Temple Houston, with Jeffrey Hunter in the title role. Elam got this part after James Coburn declined the role; the series ran for only twenty-six weeks. In 1968, Elam had an amusing cameo in Once Upon a Time in the West, where he was one of a trio of gunslingers sent to kill Charles Bronson’s character. Elam spent a good part of the scene trying to trap an annoying fly in his gun barrel. In 1969, he was given his first comedic role in Support Your Local Sheriff!, which was followed two years later by Support Your Local Gunfighter; both were opposite James Garner, after which he found his villainous parts dwindling and his comic roles increasing. (Both films were also directed by Burt Kennedy, who saw Elam’s potential as a comedian and would direct him a total of 15 times in features and television.) In between those two films, he also played a comically cranky old coot opposite John Wayne in Howard Hawks’s Rio Lobo (1970). In 1979, he was cast–ideally, some said–as the Frankenstein monster in the CBS sitcom Struck by Lightning, but the show was cancelled after only three episodes. In 1981, Elam played an eccentric doctor in the movie The Cannonball Run as Doctor Nikolas Van Helsing. In 1984, Elam once again returned in the sequel The Cannonball Run II

In 1985, Elam played Charlie in The Aurora Encounter. During this film Elam made a lifelong relationship with an 11-year-old boy named Mickey Hays, who suffered from progeria. As shown in the documentary I Am Not A Freak viewers see how close Elam and Hays really were. Elam said, “You know I’ve met a lot of people, but I’ve never met anybody that got next to me like Mickey.” In 1986, Elam also co-starred on the short-lived comedy series Easy Street as Alvin “Bully” Stevenson, the down-on-his-luck uncle of Loni Anderson’s character, L. K. McGuire. In 1988, Elam co-starred with Willie Nelson in the movie “Where The Hell’s That Gold?” In 1994, Elam was inducted into the Hall of Great Western Performers of the National Cowboy and Western Heritage Museum. Elam classified the stages of a moderately successful actor’s life, as defined by the way a film director refers to the actor suggested for a part. He was married twice, first to Jean Elam from 1937 to her death in 1961 and second, Margaret Jennison from 1961 until his death in 2003. Elam had two daughters, Jeri Elam and Jacqueline Elam, and a son, Scott Elam. Elam died in Ashland, Oregon, of congestive heart failure, a month before he would turn 83.