His mother Sheila McGuinness née Lyne, was a schoolteacher from County Kerry, Ireland.

McGuinness received his early formal education in Ireland at the private Jesuit boarding school Clongowes Wood College.

[2] Before becoming involved with U2, he worked as a film assistant director on productions such as John Boorman's Zardoz.

Following this meeting, McGuinness became U2's manager, having been introduced to the band by Bill Graham, a journalist with Hot Press magazine.

[12] He became a member of the Arts Council of Ireland on 1 January 1988, having been appointed by Charles Haughey and served until February 2000 when he resigned.

[13] On 28 January 2008, in a speech at the Midem music industry convention in Cannes, McGuinness specifically accused companies such as Apple, Google, Yahoo!, and Facebook of building "multi-billion dollar industries on the back of our content without paying for it".

McGuinness wrote the "list of ingredients" for the show: "Rich people behaving badly in the sun, yachts, Maseratis, great clothes, beautiful women, art fraud, money laundering through the auction houses, Russians, English people, American, French.