Reece Mutsinze, aged 15, left home on the evening of Wednesday June 30 and said he was heading out to meet a friend.
Derbyshire Constabulary said he has not returned home and despite it efforts, officers have been unable to find him.
He has links to Essex, Greater Manchester, Leicestershire and Nottinghamshire and may have travelled to those areas.
Reece is Black, about 6ft 2ins and of heavy build. He was last seen wearing dark jogging bottoms, a dark blue coat with a thick white stripe across the shoulders and arms, and was carrying a black bum bag.
However police believe he may have left home with clothes to change into.
Do you recognise Reece from the photo? Do you know where he might be now?
Anyone who can help should contact police quoting incident 1539 of June 30 either via a private message on Facebook, sending a direct message to @DerPolContact on Twitter, completing the online form at https://bit.ly/2a5L5jj or by calling 101.
Alternatively people can call Crimestoppers anonymously on 0800 555 111.