Jamie was last seen at his home address in Rustington around 8pm on Saturday (August 22).
He is described as white, 5′ 8″ and of medium build. When last seen, he was wearing a black hooded jumper, black trousers and green trainers, and was carrying a black rucksack.
It is thought Jamie may have travelled to the Gosport or Southampton areas of Hampshire.
Anyone who sees him or has any information as to his whereabouts is asked to contact police online or by calling 101 quoting serial 1403 of 22/08.