Montgomery was born George Montgomery Letz, the youngest of fifteen children of Ukrainian immigrant parents, in Brady, in Pondera County, northern Montana. He was reared on a large ranch where as a part of daily life he learned to ride horses and work cattle. Letz studied at the University of Montana in Missoula for a year. Montgomery was more interested in a career in film than in a college education. Therefore, he left Montana for Hollywood. Two days after his arrival there, he was working as a stunt man on a Greta Garbo film at MGM. At Republic Pictures, his cowboy skills got him stunt work and a small acting part at the age of eighteen in a 1935 film, The Singing Vagabond. He followed this with bit parts and additional stunt work as George Letz in mostly low-budget films. He was frequently cast in western films starring their number one box office draw, the singing cowboy, Gene Autry. Elevated to more important secondary roles, in 1938 he appeared as one of the six men suspected of being the titular hero in The Lone Ranger. That year Life included him in a photo montage of “Hollywood’s Movie-struck Kids” and described Montgomery, still using his full name, as “6 ft. 3 in. tall, weighs 210 lb., rides well, is superlatively handsome.” He remained with Republic Pictures until 1940 when he signed with 20th Century Fox, which billed him as George Montgomery.

At Fox, Montgomery appeared in more westerns including The Cisco Kid and the Lady (1940) with Cesar Romero. In 1942, he played opposite Gene Tierney in China Girl, jazz musician Glenn Miller in Orchestra Wives, and Ginger Rogers in Roxie Hart. The following year, Montgomery starred with Betty Grable in the Walter Lang-directed film, Coney Island. World War II interrupted his film career. He played the lead in Bomber’s Moon, released in August 1943, joined the United States Army Air Forces the same year. In 1950, he starred as the title role in Davy Crockett, Indian Scout and was one of the actors considered for the role of Crockett by Walt Disney. In the early 1950s he made several films for Edward Small and also for Columbia Pictures. In the 1958–59 season, Montgomery starred in his own 26-episode NBC Western series, Cimarron City as Mayor Matt Rockford, with co-stars John Smith and Audrey Totter through his own production company Mont Productions. . Montgomery claimed to have turned down the lead roles in the Western television series Gunsmoke and Wagon Train Montgomery produced and directed as well as starred in several films shot in the Philippines and South Africa. He planned to make a Vietnam War film The Ho Chi Minh trail in Bangkok and the Philippines but the film was aborted. Through the early 1970s, Montgomery acted in films such as Satan’s Harvest (1970) and The Daredevil (1972) and made guest appearances on a number of television shows, including NBC’s Bonanza and The Gisele MacKenzie Show.

On December 5, 1943, Montgomery married singer Dinah Shore. They had one child, Melissa Ann “Missy” Montgomery (born 1948), during a marriage that lasted until 1963. George and Dinah also adopted John “Jody” David Montgomery in 1954. In 1963, Montgomery’s private life made headlines when his housekeeper was charged in a failed attempt to kill him. Allegedly suffering from a fanatical attraction to her employer, the deranged woman planned to shoot Montgomery, then take her own life.

As a boy, George Montgomery had developed excellent craftsmanship with wood and as an adult pastime he began building furniture, first for himself and then for a few friends. His skill was such that his hobby became a full-fledged cabinet-making business in which he employed as many as twenty craftsmen. Montgomery oversaw the furniture business for more than forty years and expanded his interest to house design. He became involved with the building of eleven homes for friends and family. His artistic instincts included learning how to sculpt in bronze. Self-taught, he sculpted upwards of fifty bronze sculptures including ones of John Wayne, Clint Eastwood, Gene Autry, Randolph Scott, and future President Ronald W. Reagan. His sculpture of his former wife, Dinah Shore, and their children is at the Mission Hills Country Club in Rancho Mirage, California, home to the LPGA Kraft Nabisco Championship. After a career that included more than eighty feature films, Montgomery retired in 1972, making only two more minor appearances in film until his death at his home in Rancho Mirage, California, aged 84. After cremation, Montgomery’s ashes were divided and interred at Forest Lawn Cemetery (Cathedral City) near his Palm Springs home and at the Highland Cemetery in Great Falls, Montana, near his birthplace. For his contribution to the television industry, George Montgomery has a star on the Hollywood Walk of Fame at 6301 Hollywood Blvd. In 1995 a Golden Palm Star on the Palm Springs Walk of Stars was dedicated in his honor. He is also honored with a statue in the square of Plentywood, Montana.