The actor Roy Holder, who has died aged 75 of cancer, performed in the classics on stage and was directed by Franco Zeffirelli in film versions of two Shakespeare plays, but he will be best remembered by a generation of young television viewers for his role in a teatime fantasy series.

Ace of Wands, devised by Trevor Preston – later to write for The Sweeney and create the hard-hitting dramas Out and Fox – began in 1970, starring Michael Mackenzie as the psychic magician Tarot, fighting evil with his young assistants, played by Judy Loe and Tony Selby. Tarot, who was described in publicity as “a 20th-century Robin Hood, with a pinch of Merlin and a dash of Houdini”, also had a pet Malay fishing owl called Ozymandias.

Holder was introduced a year later as Chas Diamond, a photographer living with his sister, Mikki, a journalist, in a studio above an old London street market. They became Tarot’s new assistants for the final series, in 1972, when Holder’s storylines included sharing a dream about ancient Egypt with the mystery-solving magician and, under hypnosis, robbing a post office. “I went in as the baddie,” he recalled. “Then, they asked me to do the next series as the goodie.”

In recent years, Holder appeared at fan conventions and autograph-signing sessions for cult series such as Ace of Wands and Doctor Who, in which he appeared in the 1984 story The Caves of Androzani as Krelper, an impatient gun smuggler working for a mercenary selling weapons to an outlaw who creates androids.

Holder’s longest-running television role was in the sitcom Sorry! (1981-88) as Frank, drinking pal of the neurotic middle-aged librarian Timothy Lumsden (Ronnie Corbett), who lives with his domineering mother. “Just shut up about your mother!” Frank tells Timothy in one of his attempts to find him a partner. “Over there is a girl who likes you very much. You like her very much. Now, get to it or you’re going to find yourself neutered!”

Roy was born in Birmingham, to Florence (nee Clifford) and Frederick Holder. He was three when his father, a factory worker, died and his mother later remarried. He acted in plays while attending Upper Thomas Street secondary modern school. At the age of 15, he was plucked from a shortlist of 150 pupils by the BBC to play a “rough-looking” boy with a broad Birmingham accent for a leading role as Robert Shaw’s son in The Train Set (1961), a play written by David Turner and performed live.

Richard Attenborough was so impressed by Holder’s performance that, in his role of producer, he cast him alongside Hayley Mills as Jackie, one of the children encountering a murderer (Alan Bates) whom they mistake for Jesus Christ, in Whistle Down the Wind, one of the most popular films of 1961. Holder showed his adaptability by adopting a northern accent, reflecting the resetting of Mary Hayley Bell’s novel from Kent to Lancashire. He played a schoolboy again, alongside Laurence Olivier’s alcoholic teacher, in the film Term of Trial (1962).

After returning to TV as Bugs in the children’s serial The Chem Lab Mystery (1963), Holder established himself as a character actor in dozens of series and plays, as well as bringing his comedy skills to light entertainment in The Little and Large Show (from 1987 to 1991) and The Les Dennis Laughter Show (1990-91).

He had a starring role as the tough Sergeant Bilinski, of Six Platoon, B Company Wessex Rangers, in the army drama Spearhead (1978-81). He also played Potty, one of the Brummie anglers, in the comedy-drama series Eh Brian – It’s a Whopper (1984) and the slow-witted wagon driver Hiram Ford in Middlemarch (1994).

Holder’s early stage career included four years with the National Theatre company at the Old Vic (1964-67), during which time he had elocution lessons after Olivier told him: “My dear boy, you must lose your Birmingham accent.”

Zeffirelli, a guest director there, cast Holder in two Shakespeare film adaptations – as Biondello in The Taming of the Shrew (1967), starring Richard Burton and Elizabeth Taylor, and Peter in Romeo and Juliet (1968), with Leonard Whiting and Olivia Hussey in the title roles. Swimming with Taylor in the Mediterranean during time off was one of the actor’s happiest memories.

His other film parts included the clown in Othello (1965), one of the raw recruits in The Virgin Soldiers (1969), Bob in The Virgin and the Gypsy (1970), Hal in Loot (1970) and Fred Goddard in War Horse (2011).

In 2016, after they had been together for more than 40 years, Holder married Pauline Cox, a BBC makeup and hair designer whom he had met when they were working on the play Brent Geese in 1975.

She and their children, Kate and Thomas, survive him.

• Roy Trevor Holder, actor, born 15 June 1946; died 9 November 2021

• This article was amended on 6 December 2021. During Roy Holder’s four years with the National Theatre company, it was based at the Old Vic, not the Aldwych as an earlier version stated.