Mayweather, who retired in September 2015 after winning all 49 of his pro fights, will face a mixed martial arts fighter who has never been in a scheduled 12-round fight at the MGM Grand arena. The fight will take place in a boxing ring and be governed by boxing rules.
Mayweather said "it's official" on his Instagram account next to a picture of both fighters.
McGregor tweeted "THE FIGHT IS ON" several minutes earlier, posting a picture of himself next to one of Mayweather's father, Floyd Sr.
Mayweather will fight at the relatively advanced age of 41 in a bout that McGregor has been pushing for months. It finally came together over the last few days, and Nevada boxing officials on Wednesday approved the date for a Mayweather Promotions bout.
Report a typo to the ABC13 staff