Loi Nguyen, 16, was last seen leaving his home address in Bingley at 1pm on Monday May 31.
There have not been any confirmed sightings of him since and officers are very concerned for his welfare.
Police said Loi could be anywhere in the UK and officers are very concerned for his welfare.
Police are continuing to make urgent enquiries to trace him.
He is described as 5ft 1ins tall and of slim build with short black hair and brown eyes.
He is believed to be wearing black shoes, blue shirt, grey trousers and a light blue jacket.
Anyone with information that may assist is asked to contact police on 101 or via the West Yorkshire Police website, quoting log 1174 of May 31.