He went straight into the side, replacing Marc Pugh who had been with the Hatters on loan from Shrewsbury, but he failed to hold down a place and after playing just seven games for them, and only three of them in the Football League, he was allowed to leave at the end of his contract.
Last summer it was believed he might be heading back to Ireland with his former club Bohemian but that failed to materialise but now ahead of the new season in Ireland he's signed for St. Patrick's Athletic.
O'Connor said on completing the move: "I'm just delighted to get back playing again and I am determined to do well for St Pats. I know I won't walk straight into the team here as there are lots of good midfielders already, but I can play out wide and in the middle so I know I can play a part."