His first broadcast for RTÉ was a piece about the Lusitania for 'Newsbeat' in 1965. He later worked on 'Seven Days', but moved away from news after the programme was brought before the Lending Tribunal. In 1972, he founded the O'Herlihy Communications Group.
He then became a well-known presenter, with the catchphrase “okey-doke”. He has covered nine world cups and nine Olympics. He won a Jacob's award for his presentation of the 1990 World Cup, Irish Sports Journalist of the Year 2003, and in 2007 he was named the Irish Film and Television Academy's Television Personality of the Year.