On 28 December 2011 O'Neill was announced as the new Manager of Northern Ireland. Previous to this he was the manager of Shamrock Rovers, where he won the League of Ireland twice and the Setanta Cup once. Before this O'Neill was the manager of the Scottish team Brechin Rovers.
O'Neill's playing career took in clubs in Northern Ireland, Scotland, England and the United States. He was capped 31 times at International level.