Karl MacDermott was born in Galway. In the mid-1980s he was amongst the new breed of stand-up comedians in the Ireland of that era.

In 1988 he helped co-found The Comedy Cellar at The International Bar in Dublin with Barry Murphy, Ardal O’Hanlon and Kevin Gildea.

After appearing in his own one - man comedy show Memoirs of a Midget at The Peacock Theatre in 1989, and appearing at The Sense of Ireland Festival London 1990, he had successful runs at The Gilded Balloon in The Edinburgh Fringes from 1991-93 with shows like An Afternoon With Klaus Barbie's Pen-pal and Stand-Up Stories.

He also appeared at The Cats Laughs Comedy Festival in Kilkenny in 1997 and 1998.

By the late 1990s he stepped back from performing and concentrated on writing.

(Ahem, cough, splutter - who's he kidding? His comedy career petered out.)

Over the last twenty years he has written extensively for radio including the comedy series’ Gone But Forgotten and Here’s Johnny on RTE Radio 1 and The Mahaffys on BBC Radio 4.

He has also written two Plays of the Week for RTE Radio 1 – Friday Night and Conversations in The Dark.

In addition he has written a six-part comedy drama for RTE Two Television, Straight to Video, and has contributed many satirical articles to The Irish Times.

He found a platform to utilise his extensive knowledge of movies in 2008-2009 when he appeared with George Hook on Newstalk’s The Right Hook as movie critic.

His debut novel The Creative Lower Being was published by Killynon House Books in 2007. A second book Juggling With Turnips, a critically acclaimed collection of short comic fiction was published by Eyewear Publishing in June 2018. In September 2021, his new humour fiction novel 58% Cabbage, about a sit-down nobody who tries stand-up comedy, was published by Black Spring Press Group.