Craig Simpson, who was reported missing on December 16, has been missing on a number of previous occasions and is believed to be associating with people he knows.
He was last seen in Leeds city centre on December 22 and is believed to be regularly there.ã€€
He is described as white, 5ft 10ins tall, slim, with short brown hair.ã€€
Detective Inspector Steve Greenbank, of Leeds District Safeguarding Unit, said: "We are concerned for Craig's welfare due to his age and situation and we need to trace him and make sure he is okay."ã€€
Anyone who has seen him or who has any information that could assist in tracing him is asked to contact Leeds District Safeguarding Unit via 101 quoting reference 13160740345.