32-year-old Stephen Paxton, who is also known as Paddy, is wanted because he has breached the terms of his release licence by failing to reside at a specified address.
He was released from Hull prison on Wednesday 30 November 2011, having received a 16 month sentence in 2010 for assault.
Paxton is white, 5ft 8in tall with a heavy build and has short dark brown hair.
Although his whereabouts are unknown it is believed Paxton may be living in York.
DC Joanne Wragg, of York CID, said:
Although we do not believe Paxton poses a danger to the public, I would advise anyone who sees him not to approach him. They should ring the police or Crimestoppers, if they would prefer to remain anonymous, immediately.
If you can help to locate Stephen Paxton please contact North Yorkshire Police on 101 and press option 1.
Or call Crimestoppers anonymously on 0800 555 111 quoting reference number 12110203508.