He then committed to play four years of collegiate hockey at Notre Dame culminating in a conference championship in 2007.

O'Neill spent the majority of the year with the Monsters before he was sent to the Johnstown Chiefs of the ECHL for their playoff run.

Unable to attract an NHL offer prior to the 2010–11 season, O'Neill accepted a try-out to the reigning AHL Champions, the Hershey Bears, training camp but failed to attain a contract.

[6] As Captain of the K-Wings, O'Neill appeared in 13 games before he was signed on a professional try-out contract by AHL affiliate, the Bridgeport Sound Tigers, on November 19, 2010.

[7][8] After a second injury hit season with the Wings, O'Neill left as a free agent and signed a one-year contract with ECHL competitor the Toledo Walleye on September 4, 2012.