Dunne attended
Blackrock College, a secondary school for boys. He won the 2010 Irish Youths Amateur title; the following year, he finished third. Dunne played college golf at
University of Alabama at Birmingham. As a junior, he was named the 2014
Conference USA Golfer of the Year. As a senior, Dunne finished fifth in the individual competition at the
2015 NCAA Division I Men's Golf Championship. As a senior in college he was the Blazers' top golfer with a scoring average of 71.9. Dunne qualified for the
2014 Open Championship through final qualifying at
Woburn. He scored 75 and 73 and missed the cut by two shots. He also played in the 2014
Palmer Cup. Dunne finished his amateur career after representing Great Britain and Ireland in their 16.5 to 9.5 victory over the United States at
Royal Lytham & St Annes Golf Club in the
Walker Cup. He contributed 1.5 out of a possible 4 points over the two-day tournament.
2015 Open Championship Dunne qualified for the
2015 Open Championship by winning the Final Qualifier at Woburn; it was the second straight year he had won it. Scoring 69 in each of the first two rounds at
St Andrews, he made the cut and was the leading amateur at that stage. In the third round, he scored 66 to become joint leader at 12-under-par. He was the first amateur since 1927 to lead the Open Championship after 54 holes, and he also set a tournament record for lowest 54-hole score by an amateur. On the final day he was in the last pairing with
Louis Oosthuizen. ==Professional career==