The victim – a 24-year-old man – has been taken to Hull Royal Infirmary with serious but non-life threatening injuries.
A 39-year-old man has been arrested on suspicion of Section 18 assault and is in police custody assisting police with their enquiries.
A Humberside Police statement read: “We were called by the ambulance service at 3:20am today (Monday 17th April) reporting a man with serious head injuries outside Georgies Bar, Market Walk, Driffield.
“Localised enquiries have been conducted and a number of witnesses have been identified.
“Any witnesses who have not spoken to the police should call us on 101 quoting log 77 of 17/04/17.”