The 21-year-old victim was attacked outside Bar Rouge on Silver Street at about 4.30am on Sunday.
A 22-year-old man has been arrested on suspicion of wounding in connection with the incident and has been bailed pending further enquiries.
Halifax CID would like to speak to anyone who witnessed the assault.
Anyone who saw what happened or has any information can contact Det Con Graham Bennett on 101 referencing crime number 13180603483.
Information can also be passed anonymously to the independent Crimestoppers charity on 0800 555 111.