Daniel Smyth, aged 16, last seen in Portadown Town Centre at approximately midday on the Sunday July 8.
He was wearing a grey tracksuit and black boots.
He is known to frequent Portadown, Craigavon and Lurgan areas.
A PSNI spokesperson said: “Anyone with information regarding the whereabouts of Daniel please contact Police on 101 quoting 1661 08/07/18. You can also report anonymously through Crimestoppers on 0800 555 111.
