The playwright Paddy Chayefsky, a winner of three Academy Awards, died of cancer yesterday at Columbia-Presbyterian Medical Center in Manhattan. He was 58 years old.

Between his early great success with intimate dramas for television and his later success with large-scale Hollywood extravaganzas, Mr. Chayefsky wrote several plays for Broadway.

His most famous play was ''Marty,'' the story of a fat, unhappy butcher. First done on television, it became a movie and won an Oscar in 1955. His second Academy Award came in 1971 for ''The Hospital'' and his last in 1976 for the screenplay of ''Network,'' a grim satire on the high-pressure world of New York City television.

He often defended the artistic possibilities of films and once said of California, ''The simple truth is that Hollywood producers and executives are not the idiots they are frequently supposed to be.''

His other stories and screenplays included ''As Young as You Feel'' in 1951, ''The Catered Affair'' in 1956, ''The Bachelor Party'' in 1957, ''The Goddess'' in 1958, ''Middle of the Night'' in 1959, ''The Americanization of Emily'' in 1964 and ''Altered States'' in 1979.

Mr. Chayefsky's characters were often touching victims, unable to express their love, boredom or frustration. Defending his work against some early critics, he said in 1956: ''I have sometimes been accused of writing little plays about little people. What my critics pretend to mean, I think, is that my plays are literal and earthbound, and that my characters never achieve any stature beyond immediate recognition.''

The playwright's real first name was Sidney. His parents, Russian-Jewish immigrants, lived in the Bronx, where he was born in 1923. He attended DeWitt Clinton High School and graduated from City College with a bachelor of science degree in 1943. He then entered the Army, where he reportedly acquired the name ''Paddy'' after asking to be excused from K.P. to attend mass. He served in the 104th Infantry Division and was injured in Aachen, Germany, by a mine explosion.

While convalescing at an Army hospital in Cirencester, England, he wrote one of his first works, a G.I. musical comedy. Met Joshua Logan in Europe

The young playwright met Joshua Logan during a successful tour of the show through Europe. Ten years later, Mr. Logan produced and directed Mr. Chayefsky's first successful Broadway play, ''Middle of the Night.''

On returning home from Europe, Mr. Chayefsky went to work for a while in an uncle's print shop in Manhattan. Later, he began writing short stories and dramas for radio and television, and his early works became known for the intelligent sympathy and good humor with which he viewed his characters, many of them evidently based upon people he knew in his youth. He gained early esteem also for his naturalistic dialogue, which admirers (and later critics, for different reasons) often said resembled tape-recordings.

Some of his early television scripts are now widely forgotten, but at the time they helped persuade many critics that television was a suitable medium for serious drama. Mr. Chayefsky went so far as to write that television ''may be the basic theater of our century.'' It was an opinion he had abandoned long before he wrote ''Network.'' By then, some critics recalled Mr. Chayevsky's early work as a main reason for what they considered a ''golden age'' of television. Dramas of Early '50s

Among his television dramas of the early 1950's were ''The Mother,'' about an old woman who seeks work in a Manhattan sweatshop rather than depend on her married daughter; ''Holiday Song,'' about a cantor who has lost his faith, and ''The Big Deal,'' about a man who never made his million.

In his early work - as in his later, more violent films - Mr. Chayefsky was sometimes considered sentimental, but his characters and their fates were rarely dismissed as unbelievable.

Many scenes and bits of dialogue from Mr. Chayefsky's plays stuck in the minds of the millions who saw them. During the 1950's especially, the image of Marty - lovesick for a schoolteacher and not even knowing how he wanted to waste an evening with a friend - became famous enough to be imitated relentlessly by comedians.

Mr. Chayefsky, in his youth, had aspired to be a stand-up comic himself. He had also felt, while writing ''Marty,'' that he was writing a comedy; he was said to have been surprised when some in the audiences actually wept. 'I'm Mad As Hell'

Much later, the line ''I'm mad as hell and I'm not taking it anymore,'' from ''Network,'' gained a certain popular renown as a statement of end-of-the-rope contempt for the corruptions, hypocrisies and humiliations of corporate life and the power of society's image-makers.

Mr. Chayefsky's works were seen by tens of millions, and, whether in the plainness of his early work or in the increasing sophistication and desperation of his later characters, the author appeared to reflect certain facets of his society's changing inner life. His movies thus remained extremely popular, though his reputation among some drama critics declined.

Mr. Chayefsky also became more and more critical of American society, and his satire sharpened, seeming to some viewers to leave its naturalistic origins and enter a surreal world of hysterical comedy and pointless violence. He once said: ''Characters caught in the decline of their society - that's the essence of almost everything that I write.''

In his later years, too, he said he found the truest drama in the movies, and critics who lamented the passing of his less flamboyant plays struck him as having missed a change in society's basic tone. ''I still write realistic stuff,'' he told an interviewer. ''It's the world that's gone nuts, not me. It's the world that's turned into a satire.''

On Broadway, none of his plays lasted more than about a season, and, while often successful, their relative lack of critical attention seemed to turn him away from the stage.

His Broadway productions included ''Middle of the Night,'' ''The Tenth Man,'' ''Gideon'' and ''The Passion of Josef D'' - a play about Stalin that quickly failed.

A later play, ''The Latent Heterosexual,'' was staged in Texas, starring Zero Mostel. The drama was well received, but it did not appear in New York. Actors Acclaimed in His Roles

Several film actors gained considerable acclaim for their performances in Chayefsky works, including Ernest Borgnine in ''Marty,'' George C. Scott and Diana Rigg in ''Hospital'' and Faye Dunaway and the late Peter Finch in ''Network.''

His most recent filmscript, ''Altered States,'' about a professor who uses himself as a guinea pig for his experiments, appeared finally with a credit saying that the movie had been based on a novel by Mr. Chayefsky. The playwright had quarreled with the film's director, Ken Russell.

For about a year and a half before his death, according to the playwright's literary agent, Maurice Spanbock, Mr. Chayefsky had been working on a political play about the Alger Hiss trial.

His wife, the former Susan Sackler, whom he married in 1949, survives him, as does a son, Daniel. Mr. Chayefsky lived with his family on Manhattan's Central Park West.

Funeral services were tentatively set for 2:45 P.M. Tuesday at Riverside Memorial Chapel, 76th Street and Amsterdam Avenue in Manhattan

Sidney Chayefsky