Ellis Street-Clegg was last seen in Prescot two days ago and extensive inquiries are ongoing to find him, say police.
He is 5ft 8in tall, of slim build, with short brown hair.
Ellis was last seen dressed all in black clothing. He was wearing a black Canada Goose coat with fur around the hood and black trainers.
He has links to Liverpool, Runcorn, Widnes, Bognor Regis and Aberdeen.