The fight will take place under boxing rules at 154 pounds with 10-ounce gloves. The long-awaited fight will give Mayweather the opportunity to finish his career unbeaten with a 50-0 record, while it's McGregor's first ever boxing match.
The money involved is huge: Mayweather wanted no less then $100 million for the fight, while McGregor looks set to take home a similar amount as he will also be earning a huge amount from the UFC.
UFC President Dana White said while at times it was a struggle, overall the deal went smoothly.
“Negotiations went smooth, Floyd is surrounded by some smart people and we got this thing done. The impossible deal is now done,” White said on ESPN's SportsCenter.
"It will be in a ring, it's a boxing event. Mayweather Promotions will build the undercard for it.
"Conor McGregor is a guy who's done a lot of good things over here, for the sport and for this company. He wanted this and obviously the fans wanted it too.
"Not only for him - at the end of the day, my job is to make fights that fans want to see."
White's prediction on who would leave Las Vegas as the greatest fighter in the world today?
“I’m not saying that Conor McGregor’s gonna win, I’m not saying that Floyd Mayweather’s gonna win, but I’m telling you this: The reason Conor McGregor’s as big as he is is because he’ll fight anybody, anywhere, any time. He will go after Floyd Mayweather and he will try to knock him out.”
The fight will be Mayweather''s first in two years since his decision win over Andre Berto, while it will be McGregor's first since knocking out Eddie Alvarez at UFC 205 last November.
This fight is going to be one for the ages, and it looks set to be brutal.