Paramedics called to Ford's home just before 4 p.m. found Ford dead, police Sgt. Terry Nutall said, reading a prepared statement. "They do not suspect foul play," he said.
Ford suffered a series of strokes in the 1990s.
Failing health forced him to skip a 90th birthday tribute on May 1 at Hollywood's Grauman's Egyptian Theatre. But he did send greetings via videotape, adding, "I wish I were up and around, but I'm doing the best that I can.... There's so much I have to be grateful for."
An avid horseman and former polo player, Ford appeared in many Westerns – including "3:10 to Yuma," with Van Heflin; "Cowboy," with Jack Lemmon; "The Rounders," with Henry Fonda; "Texas," with William Holden; "The Fastest Gun Alive," with Jeanne Crain and Broderick Crawford; "Cimarron", with Anne Baxter; and "The Sheepman," with Shirley MacLaine – but his acting talents also ran to comedy and romance.
Ford appeared in scores of movies during his 53-year Hollywood career. The Film Encyclopedia, a reference book, lists 85 films from 1939 to 1991.
Ford's film credits include "A Stolen Life," a 1946 melodrama with Bette Davis playing twins in love with a lighthouse inspector; "The Teahouse of the August Moon," a 1956 satire with Marlon Brando set in U.S.-occupied Japan; "Don't Go Near the Water," a 1957 comedy about the Navy in World War II; "The Gazebo" and "It Started with a Kiss," 1959 comedies with Debbie Reynolds and a long list of actors who became beloved on television; "Pocketful of Miracles," in 1961 with Bette Davis and Peter Falk; "The Courtship of Eddie's Father," a 1963 comedy with Shirley Jones and Stella Stevens in which his romantic plans are foiled by a very young Ron Howard; and 1978's "Superman: The Movie," in which he played Jonathan Kent to Christopher Reeve's budding Man of Steel.
On television, Ford appeared in "Cade's County," "The Family Holvak," "Once an Eagle" and "When Havoc Struck."
A tireless worker -- Ford often made several films a year -- Ford continued working well into his 70s. In 1992, though, he was hospitalized for more than two months for blood clots and other ailments, and at one point was in critical condition.
"Noel Coward once told me, 'You will know you're old when you cease to be amazed.' Well, I can still be amazed," said Ford, in a 1981 interview with The Associated Press.
After getting his start in theater in the 1930s, he got a break when he was signed by Columbia Pictures mogul Harry Cohn.