ST. AUGUSTINE, Fla., Jan. 11— Richard Boone, the actor best known for his role as the hired gun Paladin in the ''Have Gun Will Travel'' television series, is dead at the age of 63. A spokesman at Craig Funeral Home in St. Augustine said today that Mr. Boone's body was to be cremated and a private service held.

The craggy-faced veteran actor, who retired here to paint in 1972 and was the state of Florida's cultural ambassador, died of cancer of the throat Saturday night at his home.

Mr. Boone won three Peabody Awards, including one for his role as Dr. Styner in the ''Medic'' television series, which ran from 1954 to 1956. He was nominated as best actor five times by the National Academy of Television Arts and Sciences.

Played Opposite John Wayne

He portrayed the late John Wayne's adversary in the films ''Big Jake'' in 1971 and ''The Shootist'' in 1976, but was better known for his television roles.

''Have Gun Will Travel,'' one of television's classic western series, was produced by CBS from 1957 to 1963. As Paladin, Mr. Boone played a black-garbed, San Francisco-based gunslinger who carried engraved business cards that announced ''Have Gun, Will Travel. Wire Paladin, San Francisco.''

At the end of the series, Boone said he was ''gratefully glad'' to be finishing it. He added, however, that ''if you have to pick a character to live with for six years, that was a good one.''

He acknowledged the series had rewarded him well financially. ''It was a ridiculous thing, but I don't ever have to worry about money,'' he said. ''As a result of playing Paladin, I have what is known to actors as a lot of go-to-hell money.'' Lived in Hawaii

In 1964, after his repertory television series was canceled, Mr. Boone left Hollywood and went to live in Hawaii for seven years. Mr. Boone, who was born in Los Angeles, was a seventh-generation nephew of the pioneer Daniel Boone. He attended Stanford University, where he studied liberal arts and won the light-heavyweight intercollegiate boxing title. Later, he worked as an oilfield roustabout in Southern California and took up painting full-time.

Mr. Boone began his acting career after he had spent four years in the Navy as an aerial gunner in World War II. He joined the Neighborhood Playhouse in New York and studied with Lee Strasberg at the Actors Studio. Was on New York Stage

He appeared on the New York stage and performed in summer stock and early television shows before making his motion picture debut in 1951 in ''The Halls of Montezuma.''

He then signed a long-term contract at 20th Century-Fox, where he made 10 films, including ''The Robe'' in 1953. During his television career, he continued to make films, including ''Man Without a Star'' in 1955 and ''The Alamo'' in 1960. His ''Rio Conchos'' was released in 1964, the same year he began his repertory television series, ''The Richard Boone Show.'' Mr. Boone was proudest of his work in that pioneering series, which used the same actors in different roles in a new play each week. The playwright Clifford Odets either wrote or supervised each play.

Among Mr. Boone's later films, were ''The Arrangement,'' 1969; ''The Kremlin Letter,'' 1970; ''The Hobbitt,'' 1978, and ''Winter Kills,'' 1978.

He also starred in the television series ''Hec Ramsey'' in 1972-73. He was once asked if he viewed television as a compromise, as compared to features. ''No way,'' he said. ''You have to pull out a whole bunch of stops day after day to keep it fresh.''

Mr.Boone is survived by his wife, Claire, a former ballerina he married in 1951; a son, Peter; a grandson; and a sister, Mrs. Don Brown of Long Beach, Calif.