Denis O'Brien is an Irish billionaire businessman, and the founder and owner of Digicel. He was listed among the World's Top 200 Billionaires in 2015 and was Ireland's richest native-born citizen for several years. His business interests have also extended to aircraft leasing, utilities support (Actavo), petroleum, football, and healthcare. As former chairman of the Esat Digifone consortium, O'Brien was questioned by the Moriarty Tribunal, which investigated the awarding of a mobile phone licence to Esat, among other things.

Digicel is a Jamaican-based Caribbean mobile phone network and home entertainment provider operating in 25 markets worldwide.