The incident happened at the Mount Inn on North Queen Street at around 7.50pm.
It was reported around 30 masked men entered the bar and one person was assaulted.
Two of those arrested are aged 25, while the third man is 47.
Detective Sergeant Adam Ruston said: “I would appeal to anyone who witnessed any cars driving away from this location at speed or anyone who noticed any car with males onboard who were wearing masks to contact detectives at Musgrave Criminal Investigation Department on the non-emergency number 101, quoting reference 1308 21/02/18.”
The public are also able to contact independent charity Crimestoppers anonymously on 0800 555 111.