The trash-talking Irish star of the Ultimate Fighting Championship wrote on Twitter that he had decided to call time on his career inside the octagon.
“Hey guys quick announcement, I’ve decided to retire from the sport formally known as ‘Mixed Martial Art’ today,” McGregor wrote. “I wish all my old colleagues well going forward in competition.
“I now join my former partners on this venture, already in retirement. Proper Pina Coladas on me fellas!”
McGregor, 30, has not fought since being well beaten by rival Khabib Nurmagomedov in October 2018.
The Dubliner, the most bankable star in the UFC, had previously vowed to retire in 2016 in a move that was widely seen as a negotiating gambit.
“I have decided to retire young. Thanks for the cheese,” McGregor wrote in April 2016. His short-lived retirement ended in August 2016, when he returned to fight Nate Diaz in Las Vegas.
McGregor’s decision comes after a troubled few weeks for the Irish fighter.
He was arrested in Miami earlier this month after allegedly smashing a phone outside a Florida nightclub.
He was later charged with criminal mischief and strong-armed robbery after police said he had slapped the phone out of a fan’s hand and then stomped on it.
McGregor is one of the most successful fighters in the history of mixed martial arts, helping to broaden the sport’s appeal beyond its base of hardcore fans.
The Irishman is estimated to have earned $200 million (B6.32 billion) from his fighting career, which included a much-hyped cross-combat bout against former welterweight boxing champion Floyd Mayweather in August 2017.