Harry Carey, Jr. was born in the Saugus neighborhood of Santa Clarita, California, the son of actor Harry Carey (1878–1947) and actress Olive Carey (1896–1988). His maternal grandfather was vaudeville entertainer George Fuller Golden. As a boy, he was nicknamed “Dobe”, short for adobe, because of the color of his hair. He served with the United States Navy during World War II.  A respected character actor like his father, Carey appeared in several Westerns. He made four films with director Howard Hawks. The first was Red River, which featured both Carey and his father in separate scenes, followed by Monkey Business, Gentlemen Prefer Blondes, and Rio Bravo. Carey is credited in Rio Bravo but his scenes were cut. Carey speculated that Hawks either did not like Carey’s outfit or cut the scene because Carey addressed Hawks as “Howard,” instead of “Mr. Hawks.” Carey made eleven films with John Wayne, starting with Red River and ending with Cahill U.S. Marshal.

Carey collaborated frequently with director John Ford, a close friend, and became a regular in what was commonly called the John Ford Stock Company. He appeared in such notable Ford films as 3 Godfathers (1948), She Wore a Yellow Ribbon (1949), Wagon Master (1950), Rio Grande (1950), The Long Gray Line (1955); Mister Roberts (1955), The Searchers (1956), Two Rode Together (1961), and Cheyenne Autumn (1964). Carey wrote a book about his experiences working with Ford titled Company of Heroes: My Life as an Actor in the John Ford Stock Company, published in 1994.

Between 1955 and 1957, Carey appeared as ranch counselor Bill Burnett in the serial Spin and Marty, seen on Walt Disney’s Mickey Mouse Club. A DVD version of The Adventures of Spin & Marty was released in December 2005 as part of the Walt Disney Treasures series. Carey was interviewed by Leonard Maltin on the 50th anniversary of the series’ debut as a DVD bonus feature.  In the 1960s, Carey appeared on such western series as Have Gun – Will Travel, The Legend of Jesse James, Wagon Train,The Rifleman, Gray Ghost, Whispering Smith, Tombstone Territory, Stoney Burke, Redigo, The Rounders, Bonanza, and Gunsmoke.

On April 29, 1962, Carey was cast as Mitch Evers in the episode “Cort” of the ABC-WB western series, Lawman, with John Russell and Peter Brown. In the story line, Cort Evers (Kevin Hagen), who is much younger than he appears, seeks revenge against his brother Mitch, whom he mistakenly blames for betraying six Union Army prisoners from their hometown during the American Civil War. Mitch is compelled to contront Cort in a shootout during which he explains that it had been Cort himself, under the influence of a fever, who betrayed the prisoners. Cort faints to the ground as he remembers the startling truth of his brother’s words.  In 1980, Carey portrayed George Arthur in the movie The Long Riders, a film about the exploits of Jesse James. In 1985, Carey played the aging biker “Red” in the movie Mask.  In 1989, Carey was a featured actor in the film, The Whales of August, with Bette Davis, Lillian Gish, Vincent Price, and Ann Sothern. In this film, Carey portrayed good natured and noisy handyman and delivered his lines in a perfect Maine accent.

In 1990, Carey appeared in the film Back to the Future Part III in a saloon scene set in 1885. In 1993, he made a cameo in the film Tombstone as Marshal Fred White.  Carey appeared in Tales from the Set, a series of video interviews in which he discussed various individuals with whom he worked. The series debuted in France at the Epona Festival, an event devoted to horses, in October 2007. In 2009, Carey and his partner Clyde Lucas completed Trader Horn: The Journey Back, a remembrance of the 1931 adventure film featuring the elder Carey. The younger Carey accompanied his father to Africa for the filming, the first motion picture filmed on the African continent by a major studio.  Carey attempted to produce a feature film called Comanche Stallion, a project which John Ford had considered making in the early 1960s, based on the 1958 book by Tom Millstead.

In 1944, he married Marilyn Fix, the daughter of actor Paul Fix. Carey died of natural causes on December 27, 2012 in Santa Barbara, California, at the age of ninety-one. His entombment was at Westwood Village Memorial Park Cemetery.