The 36-year-old former Irish international has agreed an 18-month contract at the Tallaght Stadium but he won't be fit enough to play for the club for until next month.
Dundalk begin their Champions League odyssey in Belarus this evening.
Stephen Kenny's side are away to BATE Borisov in the first-leg of their second round qualifier. Kick off there is at 6.30, Irish time.
Meanwhile Celtic play host to Icelandic side, Stjarnan in the first leg of their qualifier, with the action getting underway at Parkhead at 7.45.
