Clu Gulager, a rugged character actor who appeared in critically acclaimed films like “The Last Picture Show” as well as low-budget horror movies, and who memorably portrayed gunslingers on two television westerns, died on Friday at his son John’s home in Los Angeles. He was 93.

John Gulager confirmed the death. He said his father’s health had been in decline since he suffered a back injury several years ago.

Mr. Gulager’s rough-hewed good looks and Southwestern upbringing made him a natural for the westerns that proliferated on television in the 1950s and ’60s. He was seen regularly on “Wagon Train,” “Bonanza,” “Have Gun — Will Travel” and other shows.

An appearance as the hit man Mad Dog Coll on “The Untouchables” in 1959 persuaded the writer and producer Sam Peeples to cast Mr. Gulager as the legendary outlaw Billy the Kid on “The Tall Man,” a television series he was planning about Billy’s friendship with Sheriff Pat Garrett. (By most accounts the title was a reference to Garrett’s honesty and rectitude, and to the show’s opening credits, in which Garrett’s long shadow stretches in front of him.)

“He’s exactly what we were looking for, an actor with a flair for the unusual,” Mr. Peeples said in a TV Guide profile of Mr. Gulager shortly after the show first aired in 1960. “He lends a certain psychological depth to Billy.”

The friendship between the lawman (played by Barry Sullivan) and the gun-toting rustler was fictionalized and greatly exaggerated over the show’s 75 episodes; many historians believe that Sheriff Garrett actually shot and killed Billy in 1881. Their fatal encounter never happened on the show, which ended abruptly in 1962.

Mr. Gulager played a more lawful character on “The Virginian,” the first of three 1960s western series that ran for 90 minutes, which starred James Drury and Doug McClure. Mr. Gulager’s character on the show, Emmett Ryker, was introduced in the show’s third season when a rich man tried to hire him to murder a rancher. Although he refused to be a hired killer, he was framed for killing the man. After clearing his name, Ryker channeled his penchant for violence into the service of the law.

In Mr. Gulager’s first scene, Ryker was typically unflappable. He walked into a saloon and within moments angered a man playing cards. Ryker drew his gun on the card player before he could stand up, ending the conflict.

Moments later a deputy sheriff asked Ryker where he learned to draw like that.

“In the cradle,” he replied.

Mr. Gulager’s acting career, which lasted well into the 21st century, was not relegated to the frontier. He appeared on non-western television shows including “Alfred Hitchcock Presents,” “Knight Rider” and “Murder, She Wrote,” and in several notable movies.

He and Lee Marvin played hit men in “The Killers,” a 1964 film noir directed by Don Siegel and based on a short story by Ernest Hemingway that also starred Angie Dickinson, John Cassavetes and, in what turned out to be his last movie, Ronald Reagan.

In 1969 he played a mechanic in “Winning,” a film about auto racing with Paul Newman and Joanne Woodward. He played an older man who has a fling with his lover’s beautiful daughter in “The Last Picture Show,” Peter Bogdanovich’s celebrated 1971 study of a fading Texas town.

He was also in more lowbrow fare, like the Keenen Ivory Wayans blaxploitation parody “I’m Gonna Git You, Sucka” (1988) and the horror films “The Return of the Living Dead” and “A Nightmare on Elm Street 2” (both 1985).

His movie work continued well into his later years, including roles in the independent productions “Tangerine” (2015) and “Blue Jay” (2016). His final screen appearance was as a bookstore clerk in Quentin Tarantino’s “Once Upon a Time … in Hollywood” (2019).

Mr. Gulager left the cast of “The Virginian” in 1968 to focus on directing and teaching. (The show remained on the air until 1971, becoming the third-longest-running western in television history, after “Gunsmoke” and “Bonanza.”) His directing career foundered after the short film “A Day With the Boys” in 1969, but he became a popular teacher, running a workshop that focused on horror film acting and directing.

“I tell the young students in my class that what we do is as important as the work of a man who grows the wheat, the doctor who saves lives, the architect who builds homes,” he said in an ABC news release before he starred in the TV movie “Stickin’ Together” in 1978. “What we do, in our best moments, is provide humanity with food for the spirit.”

William Martin Gulager was born in Holdenville, Okla., on Nov. 16, 1928. He often said that he was part Cherokee; the name Clu came from “clu-clu,” a Cherokee word for the birds, known in English as martins, that were nesting at the Gulager home.

His father, John Delancy Gulager, was an actor and vaudevillian who became a county judge in Muskogee, Okla., and who taught him acting from a young age, well before he graduated from Muskogee Central High School. His mother, Hazel Opal (Griffin) Gulager, worked at the local V.A. Hospital for 35 years.

Mr. Gulager served stateside in the Marines from 1946 to 1948 before studying drama at Northeastern State College in Oklahoma and Baylor University in Waco, Texas. He continued his education in Paris, where he studied with the actor Jean-Louis Barrault and the mime Etienne Decroux.

He married Miriam Byrd-Nethery, and they acted in summer stock and university theater. In 1955 both were in a production of the play “A Different Drummer” on the television series “Omnibus.” He continued acting in New York until 1958, when the Gulagers and their infant son, John, moved to Hollywood.

Mr. Gulager’s wife died in 2003. Besides his son John, survivors include another son, Tom, and a grandson.

John Gulager is a director of horror movies, notably the gory “Feast” (2005), which starred Henry Rollins and Balthazar Getty. That film and its two tongue-in-cheek sequels also featured the older Mr. Gulager as a shotgun-toting bartender battling fanged monsters in a Midwestern tavern. The second “Feast” movie was even more of a family affair.

“You know, there are three generations of Gulagers in this movie,” John Gulager told the blog horror-movies.ca in an interview. One of them, named after Clu the elder, was Clu Gulager’s infant grandson.

“He was 11 months old when we filmed it,” John Gulager added. “My dad said, ‘We have to get Baby Clu’s career started now.’ ”

Christine Chung contributed reporting.