Conor McGregor announced his return to mixed martial arts just over a week after retiring.
The Irish star, 30, initially said on Twitter on March 26 he was retiring, but backtracked on that move on Wednesday.
Again using social media, McGregor wrote he was ready to fight again.
"I want to move forward, with my fans of all faiths and all backgrounds," he wrote on Wednesday.
"All faiths challenge us to be our best selves.
"It is one world and one for all.
"Now see you in the Octagon."
McGregor's retirement in March was a surprise, but it was also met with a lot of doubt as pundits and fighters alike questioned whether he was serious about stepping away.
After all, just a week before he was stumping for a rematch with UFC lightweight champion Khabib Nurmagomedov.
Even UFC president Dana White alluded to the fact McGregor's retirement was not for good.
"I think that there's some things that Conor wants and I think that Conor wants to get together face to face, he and I, and we probably will in the next couple of weeks and we'll get this thing figured out," White told CBS in Las Vegas.
He continued: "He's stuck on this thing where he wants a piece of the ownership and if you look at basketball, Michael Jordan didn't own a piece of the league… I think there's other ways that we can make him happy."
McGregor was already waging war on Twitter as he and Nurmagomedov traded nasty jabs on social media on Wednesday.