Dylan McEwan, from Armley, was reported missing on Monday night and police say there are concerns for his welfare given his age and the length of time he has been missing.
He is described as white, 4ft 9ins tall, slim with short ginger hair. He was last seen wearing a black Adidas jumper, black/blue jogging bottoms and blue Nike trainers.
A spokesperson for West Yorkshire Police said: "He has been missing from home previously and is thought to be with people he knows."
Anyone who has seen him or has information that could assist in tracing him is asked to contact 101 quoting log number 2110 of March 12.