[4] After finishing his schooling at fifteen, O'Herlihy followed his grandfather into journalism[5] and secured a job in the reading room of the Cork Examiner.
[6] In the early 1960s O'Herlihy began his broadcasting career when he started to do local soccer reports from Cork for Radio Éireann.
[5] After three years O'Herlihy was asked to join RTÉ's current affairs programme 7 Days to add the required field-reporting skills to the studio-based interviews.
In 1978 he became RTÉ Soccer host alongside Eamon Dunphy, in 1984 John Giles joined the panel and Liam Brady did in 1998.
[3] In 2012, while covering Chloe Magee's progress at the 2012 Summer Olympics O'Herlihy remarked that badminton was once considered "a mainly Protestant sport".
RTÉ subsequently received a number of complaints,[9] and while Magee criticised the remarks,[10] the argument was made that the incident inadvertently reflected a complex historical reality.
[19] In 2004, the Sunday Independent reported that O'Herlihy had lobbied on behalf of an Irish company, Bula Resources which was adversely affected by sanctions on Iraq.
[20][21] Environmental lobbygroup and charity An Taisce also claim that O'Herlihy's company, on behalf of a client, was involved in lobbying for controversial rezoning of land at Cherrywood in Dublin.
[22] O'Herlihy's PR consultancy was also involved in lobbying for the tobacco industry in Ireland,[23] which came under scrutiny for attempts to influence government health and budget policy.