The man suffered a broken nose after being assaulted by a group of men on Parliament Street, opposite Viper Rooms.
He was taken to Harrogate District Hospital for treatment.
Officers are appealing to anyone who witnessed the incident to contact them with information.
Anyone who can help officers with their enquiries is urged to contact North Yorkshire Police on 101 – select option 2 – and ask for Harrogate police.
If you prefer to remain anonymous, Crimestoppers can be contacted on 0800 555 111.
Please quote reference number 12140100204 when passing information about this incident.