2009-10: O'Regan attended the USA Hockey Select 15 Festival before his sophomore season at Roxbury Latin School in Massachusetts. He scored 23 goals with 21 assists for Roxbury Latin in New England Prep School League play.
2010-11: O'Regan transferred to St. Sebastian's School and played for the Cape Cod Whalers U18 midget team. He scored 25 goals with 25 assists as a junior with St. Sebastian's. In 14 games with the Whalers, including four playoff games, he scored 10 goals with 9 assists and had 2 penalty minutes. He committed to playing college hockey at Boston University in 2013-14. O'Regan was drafted by Dubuque in the eighth round (118th overall) of the 2011 USHL Entry Draft.
2011-12: O' Regan skated for Team USA at the 2011 U18 Ivan Hlinka Tournament and in the 2012 U18 World Junior Championship. O'Regan returned to Massachusetts following the Hlinka Tournament, skating for the Cape Cod Whalers U18 team and St. Sebastian's School. He joined the NDTP U18 team following the high school season and played for the gold medal-winning US squad in the U18 WJC. In three games at the Ivan Hlinka tournament, he scored 1 goal with 2 assists and was plus-two with 2 penalty minutes. He scored 5 goals with 6 assists in eight games with Cape Cod. O'Regan scored 21 goals with 35 assists and had 8 penalty minutes in 27 games for St. Sebastian's. In 14 games with the US NDTP he scored 4 goals with 6 assists. At the U18 WJC he scored 1 goal with 3 assists and was plus-six as the USA won the tournament for the third straight year. O'Regan was ranked 76th amongst North American skaters in Central Scouting's final rankings prior to the 2012 NHL Draft.
O'Regan is speedy, skilled player rolled into a small package. He may have been more highly touted had he been 6'-plus, so he'll need to prove that he can handle the bigger bodies in the pro game. But offense isn't a problem for O'Regan as he is a playmaking forward with some goal-scoring ability and enough speed to make him dangerous in the offensive zone. As with most younger players, he'll need to work on his defensive game, but that part of his game is not a major weakness.
O'Regan will play his freshman season for Boston University and as he builds strength over his development at the NCAA level, the small playmaker could become an offensive force.