[1][2][3] In a career spanning nearly sixty years, he played parts in TV productions such as Z-Cars, Dad's Army, The New Avengers and Bread.

[4][5] He also guest starred, alongside Leonard Rossiter, in an episode of Steptoe and Son, "The Desperate Hours".

[6] The writers of Steptoe and Son – Ray Galton and Alan Simpson – later said Devlin was second choice to play the part of Albert Steptoe in the series, behind Wilfrid Brambell.

[10] In 1956, he appeared in a play by Irish playwright Teresa Deevy "Light Falling"[11] where he played the part of Pat Scully, this was produced by Jack MacGowran in the Lyric Theatre (Hammersmith) as an 'opener' for Seán O'Casey play "The Shadow of a Gunman" In 1978, he had a small part in the Thames Television / Euston Films Drama The Sweeney (Season 4 Episode 5, 'Nightmare'), playing 'Hay' a handyman in an antique dealers yard.

He was Vivian Stanshall's personal choice for the role of Old Scrotum, the Wrinkled Retainer in the Charisma Films version of Sir Henry at Rawlinson End, released in 1980.