The video was filmed in the Marble Arch pub in Dublin in April and appeared to show the former UFC double champion assaulting the man, who was sitting up at the bar. Now, Conor has apologised for his actions in an interview with ESPN.
'The Notorious' MMA fighter said: "That man deserved to enjoy his time in the pub without having it end the way it did.
"I tried to make amends and I made amends back then. But it doesn't matter. I was in the wrong. I must come here before you and take accountability and take responsibility."
"Whatever comes my way, I will face it. Whatever comes my way, I deserve it.
"People are trying to bait me into things. Am I the fish or am I the whale? I must be calm, I must be zen. I must lead by example.
"I will face this head on. I will not hide from it. I was in the wrong. It was completely unacceptable behaviour for a man in my position."
The man who was punched, a 50-year-old Dubliner, has made a statement to gardai, but has reportedly told his friends that he has no interest in Conor apologising or offering him any money.
He just wants to see justice done.
The Sunday Mirror was told by a friend of the man that he was "minding his own business" when he was attacked by McGregor.
The friend said: "He was having his pint when McGregor came in and offered everyone a drink of his whiskey.
"Conor insisted he take it and when he refused a second time McGregor wasn't impressed.
"Next thing he punched him in the side of the face. He didn't feel the pain of it at the time but the next day he was in bits. It was a proper hard hit.
"His face was very sore. He was very shaken by the whole thing and didn't leave his house for days."
31-year-old McGregor is thought to have purchased a bottle of his Proper Twelve whiskey at the pub and poured shots. The man's refusal to drink one is thought to have been the flashpoint for the punch.
After the incident, the man made a statement to police and a file has been sent to the Director of Public Prosecutions. They will now decide whether to file charges against McGregor.Featured Image Credit: PA