The mixed martial arts fighter pleaded guilty to a single charge of assault on Friday.
Dublin District Court earlier heard that the victim, Desmond Keogh, did not want to give a victim impact statement.
The court was told that McGregor apologised to the victim and paid him compensation, however the amount was not disclosed to the court.
CCTV footage of the incident was played to the court.
Conor McGregor's solicitor Michael Staines said that his client accepted what he did was wrong and fully accepts the incident.
He told the court that the victim did not suffer any physical injury.
McGregor stood up in the court to address the judge.
He said what he did was "very wrong" and that he would like to apologise to the victim and to the court.
"I assure you nothing of this nature will happen again," the UFC fighter added.
Former two-weight champion McGregor has not fought since he was submitted by Khabib Nurmagomedov at UFC 229 in October of 2018, though has recently teased a comeback at the beginning of next year.