One of the most recognisable voices and faces of Irish stage and screen,[1] Kelly was known for his roles as Rashers Tierney in Strumpet City, Cousin Enda in Me Mammy, the builder Mr O'Reilly in Fawlty Towers, Albert Riddle in Robin's Nest, and Grandpa Joe in the film Charlie and the Chocolate Factory (2005).

[3] He appeared onstage in the original production of Brendan Behan's The Quare Fellow, and gained his first major career attention in Samuel Beckett's Krapp's Last Tape at the Dublin's Abbey Theatre in 1959.

[7] By then he had made his screen debut in a small part in director John Pomeroy's 1958 film noir Dublin Nightmare.

and Never Mind the Quality, Feel the Width, and particularly during the 1970s with a long-running role as the one-armed dishwasher Albert Riddle in the Man About the House spin-off Robin's Nest.

He went on to have starring roles in television shows such as Emmerdale Farm in the 1980s and Glenroe in the 1990s, as well as playing the grandfather in Mike Newell's film Into the West (1992).

[11] Kelly won a 1991 Helen Hayes Award for Outstanding Supporting Performer, Non-Resident Production, for a Kennedy Center revival of The Playboy of the Western World.