Audrey Hepburn, 63, the stage and screen actress known for her pixieish charm and her leading roles in motion picture classics such as "Roman Holiday," "Sabrina," "Breakfast at Tiffany's" and "My Fair Lady," died of colon cancer yesterday at her home in Lausanne, Switzerland.

Hepburn gained overnight cinematic stardom in 1953 with her first U.S. film, "Roman Holiday," in which she won an Academy Award as best actress in the role of a young princess who goes out incognito in Rome seeking a normal life and falls in love with a journalist, played by Gregory Peck.

She made 19 films after that, a short career by Hollywood standards, and she was nominated for four more Oscars. In the process, she won the hearts of millions of moviegoers all over the world with a delightfully mischievous elegance and a classy dignity that became her trademarks.

By the standards of the early 1950s, when the prevailing Hollywood preferences seemed to be for such buxom stars as Marilyn Monroe, Hepburn appeared to have been cast from a different cinematic mold. She was thin and girlish. But she had huge beguiling brown eyes, an elfin innocence and consummate acting skills that made her a box-office hit.

"Here is class," said Billy Wilder, who directed Hepburn in "Sabrina," a 1954 modern Cinderella romantic comedy set on Long Island. "She's like a salmon swimming upstream. . . . She's a wispy, thin little thing, but you're really in the presence of somebody when you see that girl. Not since Garbo has there been anything like it, with the possible exception of Bergman."

A native of Brussels, Hepburn spent her early teenage years in the Netherlands, which was then under the yoke of Nazi occupation. One of her brothers was taken to a Nazi labor camp, and an uncle and cousin were executed. At times she had little to eat other than turnips, and the experience had a lasting effect on her. In 1988, more than two decades after she gave up full-time acting, she turned her attention toward the plight of starving children, serving as goodwill ambassador for UNICEF. She visited destitute children in the Third World and raised money in the developed world to help them. As recently as last fall, she visited starving children in Somalia.

After World War II, Hepburn won a ballet scholarship and went to London, where she later began studying acting. She had stage roles and bit parts in British movies such as "Laughter in Paradise" and "The Lavender Hill Mob," both in 1951. The French author, Colette, saw her in a crowd scene and insisted on her for the part of "Gigi" in the play adapted from her novel of that name.

It was in the role of "Gigi" that Hepburn was introduced to U.S. audiences, and as soon as the Broadway run ended, Paramount studios starred her in "Roman Holiday."

She won a Tony Award for a Broadway appearance in "Ondine" in 1954, then gave her full attention to motion picture acting. "Sabrina," with Humphrey Bogart and William Holden, brought her a second Oscar nomination, and "The Nun's Story" in 1959 resulted in a third. Critics said this was one of her most effective dramatic performances in which, as a nun, she was compelled by her religious vows to resist the attraction she felt for a doctor, played by Peter Finch.

In 1961, Hepburn was the provocatively tarnished and flighty but also stunningly beautiful Holly Golightly in "Breakfast at Tiffany's," earning her a fourth Oscar nomination. The fifth was for "Wait Until Dark," a 1967 film in which she played a fast-thinking blind woman, terrorized by thieves in her apartment.

Her other films included "Funny Face," with Fred Astaire, and "Love in the Afternoon," with Gary Cooper, both in 1957, and "Charade" with Cary Grant in 1963. That film included one of her more memorable cinematic lines, in which she purred to Grant: "Won't you come in for a minute? I don't bite, you know, unless it's called for."

She won critical acclaim for her performance as Eliza Doolittle in "My Fair Lady" in 1964, but her selection for the role provoked a motion picture controversy. Many critics and moviegoers thought Julie Andrews, who played the part in the Broadway musical, should also have had the movie role. Hepburn lip-synched her songs in the film.

In the late 1960s she stopped making pictures regularly but returned to the screen periodically, including a role as Marian opposite Sean Connery's Robin Hood in "Robin and Marian" in 1976. In 1987, she appeared in a television movie, "Love Among Thieves." In 1989, she played an angel guide in Steven Spielberg's "Always."

Though acclaimed by critics, she always spoke modestly of her acting abilities. "I never had this huge talent or great technique," she once said. "But somehow I have had something that contributed."

In 1954, she married actor Mel Ferrer. They had a son, Sean, and were divorced in 1968.

That same year she married Andrea Dotti, an Italian psychiatrist. They had a son, Luca. They were divorced in 1980. She once said she cut back her film work after the birth of her first son in 1960 because "having children keeps you busy."