Max was reported missing after last being seen in the Huntington area at around 6.30pm on Monday (July 29).
North Yorkshire Police said he is about 5ft 10ins tall, of a slim build and had blond dyed hair, which is lighter than in this photo.
He may be wearing red shorts and a light green top with a logo on the front, the force added.
Police urge anyone who has seen Max or knows where he is to call 101 quoting reference number 12240136070.
