At around 1.30am on 18 May 2014, a 20-year-old local man was assaulted by two other men in a corridor in The Viper Rooms, on Parliament Street.
The victim sustained a broken nose in the incident.
A 27-year-old local man has been arrested in connection with the assault and has been released on police bail as enquiries continue.
Officers are still looking for the other suspect and believe the man pictured in the CCTV image can help with their enquiries.
Anyone who can help to identify the man pictured in the image or has any other information that can help the investigation is urged to contact North Yorkshire Police on 101 – select option 2 – and ask for Harrogate police.
If you prefer not to give your name, Crimestoppers can be contacted anonymously on 0800 555 111.
Please quote reference number 121401179294 when passing information about this incident.