Excelsior Rotterdam (Eredivisie)
#29 | Defender
September 2, 1993 (Age: 24)
6' 2", 190 lbs (1.88 m, 86 kg)
Born in Ireland but raised in Boulder, Colorado, O'Neill started his career as a youth player at the Colorado Rapids Academy in 2009. He was set to play his college soccer at the University of Virginia, but in June 2012 he would sign his first professional contract with the Rapids as a Home Grown Player.
O'Neill would make his debut for the Rapids in a 3-0 win over the Portland Timbers three months later.
A quite peculiar moment happened to O'Neill in August 2015 as he was first transferred by the Rapids to Apollon Limassol in Cyprus. However, within the same month, and without playing a single game for Apollon, he was sent on loan to Royal Mouscron-Péruwelz in the Belgian Pro League.
Following a brief stop in Belgium, O'Neill would be on the move again as he was sent on loan to Cambridge United in England's League Two.
In the 2016-2017 season, O'Neill would be sent on loan again. This time to the Netherlands, where he played for Eerstedivisie team NAC Breda. The move would be a successful one as he helped them earn promotion to the Eredivisie for the 2017-2018 season.
In August 2017, after failure to make his move to the NAC Breda permanent, O'Neill signed a one-year deal with fellow Dutch Eredivisie team SBV Excelsior.
Having dual Irish and U.S. citizenship, O'Neill has so far opted to represent the United States.
While he has not featured for the senior team, he has represented the U.S. at the Under-20 and Under-23 levels.