LOS ANGELES, Nov. 15--Lionel Barrymore died tonight at Valley Hospital in Van Nuys. He was 76 years old. His physician, John Paul Ewing, attributed his death to a heart ailment.

The actor was stricken last night at the home of Mrs. J. E. Wheeler. He had resided with Mrs. Wheeler and her two daughters, Miss Benson Wheeler and Miss Florence Wheeler, for the last eighteen years.

Mr. Barrymore was taken to the hospital and placed in an oxygen tent. Dr. Ewing said he lapsed into unconsciousness about midnight and failed to respond to treatment.

Lionel Barrymore once estimated that members of his famous family of the Drews and the Barrymores had appeared on the stage for 200 continuous years. He, himself, despite his protests that his interest in acting had arisen only from a necessity to eat, accounted for 61 of these years.

Mr. Barrymore, although he would have preferred to be an artist and composer, became an outstanding success of stage, screen and radio. His yearly radio interpretation of Scrooge in Dickens' "Christmas Carol" became traditional. In his later years when a hip injury confined him to a wheelchair, it was a tribute to his popularity and ability that parts were written around him and audiences never questioned the appearance of an actor in a wheelchair. Born in Philadelphia April 28, 1878, he was the eldest of the three children of Maurice (Blythe) and Georgie (Drew) Barrymore. He was also later to be known as the quietest of the triumvirate of Lionel, Ethel and John, born in that order.

His reluctant stage debut came at the age of 6 when the Barrymores were on tour. He was pressed into action when a child actor became ill. When he followed up his cue with a good cry instead of his lines, he was retired from the stage by his famous parents until he was 15.

At that time another of his family, his grandmother, the prominent Louisa (Mrs. John) Drew, ventured on the stage with him in "The Rivals." His debut with the famous Mrs. Malaprop of her time was apparently successful, for he next appeared with her in "The Road to Ruin."

Took to Painting

Mr. Barrymore, who was already proclaiming his desire not to act, then left the stage to study painting for three years. The attempt was not outstanding and he returned to acting, appearing in "Squire Kate," "Cumberland '61" and several plays with Nance O'Neil's company.

He toured with the late J. A. Herne in "Sag Harbor," was cast with his uncle, John Drew, in "Second in Command," and by 1904 had appeared in many more works and was counted as a star.

In 1904, having married Doris Rankin, the young sister of his uncle Sidney Drew's wife, Mr. Barrymore, still determined to become an artist, went to Paris with his bride where he continued his painting studies for several years.

Returning to New York and still plagued with the need to earn a living, he heard of D. W. Griffith's movie-making enterprise in the Biograph Studios on Fourteenth Street. He asked for a job. Disclaiming an interest in "stars" Mr. Griffith, according to Mr. Barrymore's account of the incident, reluctantly hired the six-foot, dark-haired young man at $10 a day.

One of the first pictures made by Mr. Barrymore in those early days of silent movies was "The New York Hat," with a young actress, Mary Pickford. The script, her first, was written by Anita Loos. Others of his co-workers were Mabel Norman, Lillian and Dorothy Gish, Mack Sennett and James Kirkwood. Many of the scripts of the first two-reelers were written by actors. Mr. Barrymore himself admitted to having written "dozens" at $25 apiece.

When, as he said, he was brought "kicking and protesting back to the stage," it was one of his most famous roles, that of Colonel Ibbetson in "Peter Ibbetson," in 1917. The next year he was persuaded to leave the play for the role of Milt Shanks in "The Copperhead," described by the late Heywood Broun as "the best piece of acting I ever saw."

It was to see Lionel in this part that John Barrymore, the incorrigible brother, bought out the whole house of his own play, "Peter Ibbetson," in which he was appearing in Hartford. It developed later that John's boss, Lee Shubert, had refused to let John pay for the expensive $3,000 ticket to his brother's opening night.

Lionel followed up this success in 1921 with "Macbeth," described as the hit of the season. The same year, starring in "The Claw," Mr. Barrymore met Irene Fenwick, who became his second wife July 14, 1923, after his divorce from Doris Rankin. The marriage was known as a happy one. Mrs. Barrymore retired from the stage soon after the marriage. She died Christmas Eve in 1936.

Before he "escaped permanently to California" in 1925, he had also played in "Laugh, Clown, Laugh," "The Piker" and "Man or Devil." In the movies he made what was known as "quickies" until the Thirties, when he again became a star in that medium.

"Free Soul," in which he portrayed a drunkard lawyer defending his daughter against a murder charge, won him an Academy Award for the best performance of the year in 1931. From then on, his movies, made with some of the biggest stars in Hollywood, included "Grand Hotel," "Reunion in Vienna," "Dinner at Eight," "Treasure Island" and "David Copperfield."

Three Appear in 'Rasputin'

The three Barrymores appeared together in "Rasputin and the Empress." It was Lionel and Ethel's first appearance together since Ethel staged a production of "Camille" when she was 10. That early performance, with Lionel starred as Armand, also marked his first and last appearance in a romantic role. He declined to be cast in such a part after the experience.

In 1938, "Young Dr. Kildaire," the first in the well-known series, appeared. This was the year that Lionel, after several years' in and out of his wheelchair with a hip injury had the final accident that confined him to the chair for the rest of his career.

While he was gaining his reputation on the stage, screen and in radio, he also received recognition for his artistic and musical achievements. Several of his etchings were grouped with the "Hundred Prints of the Year," and he was elected to the Society of American Etchers.

In the summer of 1944, his symphony, "Partita," was performed at Lewisohn Stadium by Fabien Sevitzky. "In Memoriam," a tone poem in memory of his brother, John, who had died in 1942, was performed by the Philadelphia Orchestra under Eugene Ormandy. "Tableau Russe," another of his compositions, was presented in the Hollywood Bowl. The theme song for the "Mayor of the Town" radio feature, in which he played the sage and samaritan mayor, was also his composition.

As recently as 1952 another of his compositions was presented on records. This was a musical setting of "Ali Baba and the Forty Thieves" with the composer as the narrator.

Narrator for Record Album

He was narrator for an album of records made during World War II by the Armed Forces Radio service, entitled "Great Music." He was active in community affairs, often appearing in benefits for special civic causes. At one time he was chairman of the national board of sponsors of the National Arthritis Research Foundation.

Mr. Barrymore's political activity in behalf of Governor Dewey during the 1944 Presidential campaign was reported to have brought a protest from the Roosevelt family when Metro- Goldwyn-Mayer announced him for the role of Franklin Delano Roosevelt in the film "The Beginning of the End," in 1946. He was withdrawn from the picture.

In May, 1951, Mr. Barrymore added writing to his creative achievements. His book, "We Barrymores," written with Cameron Shipp, was published by Appleton-Century-Crofts, Inc.

Mr. Barrymore also wrote a novel, "Mr. Cantonwine: A Moral Tale," published by Little, Brown & Co. The story was about a snake-oil peddling preacher.

Last March, he was one of a group of motion-picture stars who received Treasury Department citations for cooperation in helping to promote investment in United States Savings Bonds.

His sister, Ethel, survives.