It's official -- Conor McGregor is now in the knucklin' business ... putting pen to paper on his Bare Knuckle Fighting Championships ownership papers!!
Notorious was joined by BKFC founder and president David Feldman at McGregor's Black Forge Inn in Dublin on Thursday for a bit of a ceremonial signing ceremony ... and the two looked thrilled about the big moment.
"Rocket to the moon, brother," Conor said. "Take off the gloves and fight, bitch!!"
Of course, Conor made the big announcement at KnuckeMania 4 a few weeks back .