Widmark's wife, Susan Blanchard, said he died Monday. She would not provide details of his illness and said funeral arrangements are private.
"It was a big shock, but he was 93," Blanchard said.
After a career in radio drama and theater, Widmark moved to films as Tommy Udo, who delighted in pushing an old lady in a wheelchair to her death down a flight of stairs in the 1947 thriller "Kiss of Death." The performance won him an Academy Award nomination as supporting actor; it was his only mention for an Oscar.
"That damned laugh of mine!" he told a reporter in 1961. "For two years after that picture, you couldn't get me to smile. I played the part the way I did because the script struck me as funny and the part I played made me laugh. The guy was such a ridiculous beast."
A quiet, inordinately shy man, Widmark often portrayed killers, cops and Western gunslingers. But he said he hated guns.
"I know I've made kind of a half-assed career out of violence, but I abhor violence," he remarked in a 1976 Associated Press interview. "I am an ardent supporter of gun control. It seems incredible to me that we are the only civilized nation that does not put some effective control on guns."
Two years out of college, Widmark reached New York in 1938 during the heyday of radio. His mellow Midwest voice made him a favorite in soap operas, and he found himself racing from studio to studio.
Rejected by the Army because of a punctured eardrum, Widmark began appearing in theater productions in 1943. His first was a comedy hit on Broadway, "Kiss and Tell." He was appearing in the Chicago company of "Dream Girl" with June Havoc when 20th Century Fox signed him to a seven-year contract. He almost missed out on the "Kiss of Death" role.
2"The director, Henry Hathaway, didn't want me," the actor recalled. "I have a high forehead; he thought I looked too intellectual." The director was overruled by studio boss Darryl F. Zanuck, and Hathaway "gave me kind of a bad time."
An immediate star, Widmark appeared in 20 Fox films from 1957 to 1964. Among them: "The Street With No Name," "Road House," "Yellow Sky," "Down to the Sea in Ships," "Slattery's Hurricane," "Panic in the Streets," "No Way Out," "The Halls of Montezuma," "The Frogmen," "Red Skies of Montana," "My Pal Gus" and the Samuel Fuller film noir "Pickup on South Street."
In 1952, he starred in "Don't Bother to Knock" with Marilyn Monroe. He told an interviewer in later years:
"She wanted to be this great star but acting just scared the hell out of her. That's why she was always late - couldn't get her on the set. She had trouble remembering lines. But none of it mattered. With a very few special people, something happens between the lens and the film that is pure magic. ... And she really had it."
After leaving Fox, Widmark's career continued to flourish. He starred (as Jim Bowie) with John Wayne in "The Alamo," with James Stewart in John Ford's "Two Rode Together," as the U.S. prosecutor in "Judgment at Nuremberg," and with Robert Mitchum and Kirk Douglas in "The Way West." He also played the Dauphin in "St. Joan," and had roles in "How the West Was Won," "Death of a Gunfighter," "Murder on the Orient Express," "Midas Run" and "Coma."
"Madigan," a 1968 film with Widmark as a loner detective, was converted to television and lasted one season in 1972-73. It was Widmark's only TV series.
He also was in some TV films, including "Cold Sassy Tree" and "Once Upon a Texas Train."
Richard Widmark was born Dec. 26, 1914, in Sunrise, Minn., where his father ran a general store, then became a traveling salesman. The family moved around before settling in Princeton, Ill.
"Like most small-town boys, I had the urge to get to the big city and make a name for myself," he recalled in a 1954 interview. "I was a movie nut from the age of 3, but I don't recall having any interest in acting," he said.
But at Lake Forest College, he became a protege of the drama teacher and met his future wife, drama student Ora Jean Hazlewood. They were married for 55 years, until her death in 1997.
In later years, Widmark appeared sparingly in films and TV. He explained to Parade magazine in 1987: "I've discovered in my dotage that I now find the whole moviemaking process irritating. I don't have the patience anymore. I've got a few more years to live, and I don't want to spend them sitting around a movie set for 12 hours to do two minutes of film."
When he wasn't working, he and his wife lived on a horse ranch in Hidden Valley, Calif., or on a farm in Connecticut. Their daughter Ann became the wife of baseball immortal Sandy Koufax.