William Smith, an actor known for his portrayals of villains and his onscreen movie brawls, died on Monday in Woodland Hills, Calif. He was 88.

Mr. Smith’s wife, Joanne Cervelli Smith, said he died at the Motion Picture and Television Fund’s Country House and Hospital. She did not specify the cause.

While Mr. Smith was best known for his roles in action movies like “Any Which Way You Can” (1980), and television shows including “Laredo,” “Rich Man, Poor Man” and “Hawaii Five-O,” the real action came from his offscreen life.

He was a polyglot, a bodybuilder, a champion discus thrower and an Air Force pilot during the Korean War, according to his website.

Mr. Smith had more than 300 acting credits listed on IMDb from 1954 to 2020. He did many of his own stunts, and sometimes those scenes got heated. He was throwing punches with Rod Taylor for the 1970 film “Darker Than Amber” when the two began fighting each other for real. Both walked away with broken bones.

“Now that was a good fight,” Mr. Smith recalled in a 2010 interview with BZ Film.

The Columbia, Mo., native solidified his Hollywood status after tussling onscreen with actors like Clint Eastwood, Nick Nolte and Yul Brynner. In the 1980s, the 6-foot-2 actor earned roles in Francis Ford Coppola’s “The Outsiders,” (1983) and in “Conan the Barbarian” (1982), for which he was cast as the father of Conan, who was played by Arnold Schwarzenegger.

His last role was in “Irresistible,” a 2020 film directed by Jon Stewart.

In “Rich Man, Poor Man,” he played the dangerous and eccentric character Anthony Falconetti, which he would later reprise in a follow-up to the series, “Rich Man, Poor Man Book II.”

Mr. Smith, who was born on March 24, 1933, grew up on a cattle ranch in Missouri owned by his parents, William Emmett Smith and Emily Richards Smith. At the ranch, he would develop a love and admiration for horses and the classic Western lifestyle, according to his website.

His family later moved to Southern California, and Mr. Smith immediately began to seek work in films, finding jobs as a child performer and later as a studio extra.

Ms. Smith said in a phone interview on Sunday that besides the tough guy roles that made her husband a star onscreen, he had a compassionate side as well. “He’s definitely tough as nails but he had the heart of a poet,” she said.

In 2009, Mr. Smith published a book of poetry, “The Poetic Works of William Smith.”

The place to find Mr. Smith, even as an older man, was the gym, Ms. Smith said. Young actors often would talk to him between workout sets, and he would share advice, sometimes inviting them to his home to discuss upcoming auditions.

In addition to his wife, Mr. Smith is survived by his son, William E. Smith III, and his daughter, Sherri Anne Cervelli.

Alyssa Lukpat contributed reporting.