Police are asking members of the public to report any sightings of Gavin Knight, 37, from Selby, who was last seen in York.
Gavin left his home on Thursday 8 December to visit a friend in the Chaloners Road area of York.
He was last seen by his friend’s family on the afternoon of 8 December, but he has not returned home or been seen since.
Officers are growing increasingly concerned for his safety and are appealing to anyone who may have seen Gavin, to get in touch.
Gavin is described as white, 5ft 6in tall, of stocky build with green eyes, mousey coloured receding hair, a beard and a moustache.
He was last seen wearing a dark green jacket with fur around the hood, a black hoody, grey tracksuit trousers, and blue or black plimsoles.
Anyone who has seen Gavin is asked to call North Yorkshire Police on 101. If you have an immediate sighting of Gavin or know where he is now, please call 999.
Please quote reference number 12220219052