Joss Ackland, a self-described workaholic actor who appeared in more than 130 movies, TV shows and radio programs, most notably — for American audiences, at least — as a villainous South African diplomat in “Lethal Weapon 2,” died on Sunday at his home in Clovelly, a village in southwestern England. He was 95.

His agent, Paul Pearson, confirmed the death.

He was a renowned character actor onscreen, having held memorable supporting roles in movies like the Cold War thriller “The Hunt for Red October” (1990) and the hockey comedy “The Mighty Ducks” (1992). He also earned a British Academy Film Awards nomination for “White Mischief” (1987), a drama set in colonial Kenya. But Mr. Ackland’s true home was the London stage.

He was among the actors who provided the firm foundation of English theater during the postwar years, ranking alongside Ian Holm, Maggie Smith and Claire Bloom. Many in that generation, like Mr. Ackland, later found success in Hollywood.

A bear of a man with a gravelly voice and a gregarious, opinionated presence onstage and off, Mr. Ackland was prolific and versatile. He played Falstaff, Shakespeare’s great comic character in “Henry IV, Part 1” and Henry IV, Part 2”; the writer C.S. Lewis in the British TV version of “Shadowlands”; and Juan Perón in the original London cast of Tim Rice and Andrew Lloyd Weber’s “Evita” (1978), opposite Elaine Paige in the title role.

“I don’t think I’ve made any role my own,” he told The Evening Standard in 2006. “My quality is variation. I’m a hit- and-run actor. I get to do a lot of villains, but that’s because I’m English.”

Mr. Ackland could be self-disparaging about his willingness to take work wherever it became available, a predilection driven less by money than a need to be constantly on the move.

He came to regret many of his nontheatrical roles, like those in the comedy “Bill and Ted’s Bogus Journey” (1991) and a meaty cameo in the video for the song “Always on My Mind” by the English pop band the Pet Shop Boys.

“I do an awful lot of crap, but if it’s not immoral, I don’t mind,” he told The Guardian in 2001. “I’m a workaholic. Sometimes it’s a form of masochism.”

He was even ambivalent about his role in “Lethal Weapon 2” (1989) as Arjen Rudd, the oily, racist South African who battles two Los Angeles police detectives, Martin Riggs (Mel Gibson) and Roger Murtaugh (Danny Glover).

Rudd, a consul-general dealing drugs on the side, gets away with murder by claiming diplomatic immunity, even at the point where he appears to kill Riggs — just before Murtaugh shoots him in the head.

“It’s just been revoked,” Murtaugh says, a punchline that became a catchphrase of the late 1980s, much to Mr. Ackland’s chagrin.

“Not a day goes by without someone across the street going ‘diplomatic immunity,’” he said in a BBC interview in 2013. “It drives you up the wall.”

Sidney Edmond Jocelyn Ackland was born on Feb. 29, 1928 — a leap day — in the North Kensington neighborhood of London. His father, Sydney Ackland, was a journalist from Ireland whose serial philandering kept him largely out of his son’s life, leaving him to be raised by his mother, Ruth Izod, a maid.

He gravitated to acting as a child, inspired, he later said, by the mysterious smoke and fog of Depression-era London.

“To be in the fog was to be in an adventure where the imagination could stretch itself, allowing me to be anywhere in the world,” he told The Independent in 1997. “Houses and streets would disappear, and a lamppost would faintly emerge from the gloom and become a pirate ship.”

He attended the Royal Central School of Speech and Drama in London, paying his way by cleaning barracks for U.S. Army troops stationed there during World War II. He graduated in 1945, the same year he started acting professionally.

Mr. Ackland spent decades performing in repertory and small-town theater. In 1951, he traveled to Pitlochry, a small town in the Scottish Highlands, to appear in J.M. Barrie’s play “Mary Rose.” Among his fellow actors was Rosemary Kirkcaldy.

Though she was engaged at the time, the two fell in love and married later that year.

With a growing family — the couple eventually had seven children — Mr. Ackland despaired of making a career in acting. In 1955, he and his wife, with two infants in tow, moved to East Africa, where he spent six months running a tea plantation in Malawi.

But the stage beckoned, and they spent two years in South Africa picking up acting work. The country’s intrusive apartheid regime disgusted them; at one point the police raided their home looking for subversive material and left with a copy of the novel “Black Beauty,” the tale of a horse by Anna Sewell, which investigators thought might be anti-apartheid.

After returning to Britain, the couple restarted their careers, even as their family was growing rapidly.

One evening in 1963, when Mr. Ackland was performing as the lead in Bertolt Brecht’s “Life of Galileo,” a fire broke out in their London home. Ms. Kirkcaldy, pregnant with their sixth child, managed to get the other five out of the house but broke her back when she leaped from an upper floor.

Doctors said she would miscarry and never walk again; instead, she delivered a healthy child and was on her feet again within 18 months.

Ms. Kirkcaldy was diagnosed with motor neuron disease in 1999 and died in 2002. Mr. Ackland is survived by his daughters Kirsty Baring and Sammy, Penny, Melanie and Toni Ackland; his son Toby; 34 grandchildren; and 30 great-grandchildren. Another son, Paul, died in 1982.

After his wife’s death, Mr. Ackland developed stage fright and stayed away from theater for 12 years, he said. During that time, he edited her diaries, a project she had encouraged him to pursue, and published them in 2009 as “My Better Half and Me: A Love Affair That Lasted Fifty Years.”

He returned to the theater in 2012 to play King George V in David Seidler’s play “The King’s Speech” (later adapted as a movie). By then, he had soured on the turns that his profession had taken toward instant stardom and pyrotechnic productions.

“They give them all these car chases, the villain dying twice, and they play down to the audience,” Mr. Ackland told Strand magazine in 2002. “But I believe you should never give people what they want. Give them something a little more than what they want and that way they grow up.”