Gardaí at Portlaoise Garda Station are looking for the public's help in tracing Thomas Doyle Molloy.
The 17-year-old has been missing since October 22.
Thomas is 5"10, ten stone and of slim build. He has brown hair and blue eyes.
The teenager is known to frequent Dublin city centre, Tallaght and Dundrum areas.
Anyone with information on Thomas' whereabouts should contact Portlaoise Garda Station at 057-867-4100.