Carey, whose career spanned more than 50 years and included such Ford classics as "She Wore a Yellow Ribbon" and "The Searchers," died of natural causes in Santa Barbara, said Melinda Carey, a daughter.
"In recent years, he became kind of the living historian of the modern era," film critic Leonard Maltin told The Times on Friday. "He would get hired on films by young directors who just wanted to work with him, to be one step away from the legends. Some hired him to just hear his stories between takes."
Director Joe Dante, who used Carey in his 1984 comic-fantasy "Gremlins," told The Times in 2003: "You got a lot of free movie history when you cast him."
The son of silent-film western star Harry Carey Sr. and his actress wife, Olive, Carey made more than 100 films. They included "Red River," "Beneath the 12-Mile Reef," "Big Jake," "Cahill U.S. Marshal," "The Long Riders," "The Whales of August" and 1993's "Tombstone."
The boyishly handsome Carey lacked the screen-dominating star quality of his longtime pal and frequent co-star, John Wayne. Instead, Carey brought a rare authenticity to his westerns as one of Hollywood's best horsemen.
That was amply illustrated in 1950's "Rio Grande," for which he and cowboy-turned-character actor Ben Johnson learned to ride two horses while standing up, with one foot on the back of each horse.
His other films with Ford include "3 Godfathers," "Wagon Master," "The Long Gray Line," "Mister Roberts," "Two Rode Together" and "Cheyenne Autumn."
Carey also appeared in dozens of television shows, most of them westerns, and portrayed the boys' ranch counselor in the popular 1950s "Spin and Marty" serials on "The Mickey Mouse Club."
According to Dante, Carey was at his best in Ford's 1950 western "Wagon Master," in which Carey and Johnson co-starred as horse traders who join a Mormon wagon train.
"Harry was a straight-arrow, realistic person on the screen," Dante said. "It didn't seem like he was acting. He really had an aw-shucks quality."
He was born Henry George Carey on May 16, 1921, on his father's ranch north of Saugus and a 45-minute drive from Universal Studios, where Harry Sr. made westerns in the 1910s and 1920s. More than two dozen were directed by John Ford, who became a close family friend.
When Carey was born, his father, Ford and then-New York City Mayor Jimmy Walker awaited the baby's arrival by drinking a whiskey named Melwood.
From then on, as Carey wrote in his 1994 memoir, "Company of Heroes: My Life as an Actor in the John Ford Stock Company": "Every time Ford saw me with my father he'd say, 'Mellllwood … li'llll Mellllwood,' alluding to how drunk he and my dad were that night."
The young Carey graduated from Black-Foxe Military Institute in Hollywood in the late 1930s, studied voice and made his stage debut, with his father, in summer stock in Maine.
During World War II he served in the Navy in the Pacific theater, then worked in Washington on Navy training and propaganda films for Ford, at that time a naval officer.
In 1944, Carey married Marilyn Fix, daughter of character actor Paul Fix.
After the war, Carey attempted a singing career but turned to film with a small role as a cowboy in the 1946 movie "Rolling Home."
"When he went into the movies, everybody suggested he go by Harry Carey Jr., but I think he regretted that forever," his daughter said. "He just wanted to be Dobe, the nickname he always went by," and which his father gave him because his red hair matched the ranch house's adobe bricks.
John Wayne recommended the fledgling actor for the role of a cowboy who dies in a cattle stampede in the 1948 Howard Hawks' classic "Red River." Shot in 1947, it also featured the elder Carey in his final role. He died the same year at 69.
When Ford made "3 Godfathers," he cast Harry Jr. in a leading role as the Abilene Kid and dedicated the 1948 film to Harry Sr. The film's three desperadoes — played by Wayne, Pedro Armendariz and Carey — risk their lives in the desert to save a baby.
Before filming in Death Valley, Ford — who was well-known for his sadistic behavior toward actors in his films — told Carey: "You're going to hate me when this picture is over, but you're going to give a great performance."
After the first take of Carey's death scene, filmed in scorching heat, Ford cussed him out and left the actor to bake in the sun for 30 minutes. When the director returned, a near-delirious Carey delivered his death speech, his mouth so dry he couldn't swallow and with a voice that resembled the croaking of a dying man.
"Why didn't you do that the first time?" a grinning Ford told Carey. "See how easy it was? You done good! That's a wrap!"
Carey is survived by his wife, Marilyn; daughters Melinda and Lily; son Tom; three grandchildren; and two great-grandchildren.