The incident happened at Montey's at 1am on Sunday 3 September and involved a man being assaulted with glass, causing injury to his face.
The victim was taken to hospital to receive treatment for his injuries.
Officers are asking members of the public to get in touch if they recognise the man in the image as they believe he could have information that will help with their investigation.
Anyone with any information is asked to email Sam.Clarke2@northyorkshire.police.uk or call North Yorkshire Police on 101, select option two and ask for Sam Clarke.
If you wish to remain anonymous, you can pass information to Crimestoppers by calling them on 0800 555 111.
You should quote the North Yorkshire Police reference number 12230166084 when passing on any details.