Justin O’Neill was born in Warwick, Queensland, Australia, and is of Ni-Vanuatu descent through his mother.
Former Maroons and Kangaroos centre Justin O’Neill has announced his retirement, effective immediately, due to a chronic knee injury.
In September 2012, O’Neill was named in Vanuatu’s train-on squad for their match against Greece on 20 October 2012 but O’Neill did not play in the match, though some sources indicate that he did. He was a trainer for Vanuatu in their match against the Solomon Islands in October 2013.
O’Neill’s mother Nicole represented Vanuatu in the 100 and 200 metres at the South Pacific Games.