Creedon's career began with an initial failed audition for a job on RTÉ 2fm, but he went on to twice top the Irish Singles Chart with his character, Terence the Cork hairdresser.

In August 2008 Creedon took part in the reality television series, Fáilte Towers,[10] a show that saw a group of well-known personalities attempt to run a hotel for a two-week period whilst earning money for charity.

"[12] After his victory, he presented a show for the RTÉ Concert Orchestra[13] and partook in TG4 series Faoi Lan Cheoil where, alongside Oscar-winning actor Jeremy Irons and international and Premier League footballer Andy Reid, he learnt a new musical instrument over six months in preparation for a public performance.

[14] Creedon was then a judge on The All Ireland Talent Show, representing the south of the country alongside Michael Healy-Rae and Sinéad Sheppard.

[21] After his turn on Fáilte Towers, journalist and RTÉ colleague Joe O'Shea described Creedon's personality as being that of "somebody who gives space to others and is not intent on sucking up all of the available on-screen oxygen".

[22] In March 2008, it was to Creedon's radio show that befuddled Irish listeners turned when RTÉ shut down its 82-year-old medium wave service.

Within hours of the shutdown, they were contacting John Creedon's RTÉ radio show, "wondering how they could tune in to the newfangled VHF – or “VHI’’, as one gentleman insisted on calling it".

While it did upset him at the time he recalls that his daughter Nanci told him "I’d rather be a third-rate presenter than a first-rate critic" a sentiment to which he says “I’ve kept that one in my back pocket, d’you know?”.

His musical taste is eclectic, ranging from local band Fred to The Beatles, Nina Simone, Bruce Springsteen and Van Morrison.