(TMZ) -- IT'S HAPPENING!!!

Floyd Mayweather has signed his deal and will box Conor McGregor on August 26. 

Dana White was leading the negotiations for the UFC -- and had vowed to strike a deal with Floyd's camp. Now, the two sides have reached an agreement, as first reported by Yahoo News. 

Conor and Floyd will square off in Vegas. 

Conor posted about the fight on Instagram -- saying, "The fight is on." He replaced Floyd's pic with a shot of Floyd Sr. 

THE FIGHT IS ON.

A post shared by Conor McGregor Official (@thenotoriousmma) on

Conor has said he expects to make more than $100 MILLION from the fight. Floyd has said he wanted double or triple that. No word on the exact details. 

The last time we spoke with Floyd, he laid out exactly why he thinks Conor has a real shot to beat him.