Georges St-Pierre, one of the most popular and successful MMA fighters of all time, will announce his retirement on Thursday at a 10:30 AM press conference in Montreal, Canada.
The news was first reported by Benoit Beaudoin of RDS in Canada and verified by ESPN.
The 37-year-old St-Pierre last competed in November 2017 after four years out of the sport, defeating Michael Bisping by third round submission to win the UFC middleweight championship. He vacated the belt after a month after he revealed he was suffering from colitis and didn't want to hold up the division.
His name had been brought up repeatedly over the last year-plus for potential fights with Conor McGregor, Anderson Silva, and Khabib Nurmagomedov, but UFC president Dana White continually shot the notion of GSP returning down.
ESPN's Ariel Helwani tweeted that when efforts at making a Nurmagomedov fight fell through, the decision to retire was made.
St-Pierre made his pro debut in January 2002 and after five fights, he made his UFC debut two years later. What followed was two runs with the UFC welterweight title, one interim welterweight title win, nine successful title defenses, and a 13 fight win streak to end his career.
He left the sport after a controversial split decision win over Johny Hendricks at UFC 167 in November 2013, saying he needed to take time off -- a decision that fractured his relationship with White and UFC ownership.
During his run, he elevated the UFC's brand in Canada, making them a financial bonafide hotbed for MMA during the post-TUF boom period. He headlined the company's first-ever stadium show, UFC 129 in Toronto, Canada, in front of nearly 56,000, and during his run, he defeated the likes of Bisping, B.J. Penn, Matt Hughes, Frank Trigg, Nick Diaz, Carlos Condit, and Josh Koscheck among others.
He also became one of the few fighters of that era to crossover into mainstream pop culture. He signed a deal with Under Armour, one of the few mainstream sports apparel deals an MMA fighter had, and even played the role of Batroc in the Captain America sequel.