The Houston Chronicle first reported the matchup and UFC officials confirmed the bout as the UFC 166 co-main event on Monday.
Cormier (12-0) is a former Olympic wrestler who transitioned into mixed martial arts. He made his professional MMA debut in 2009 and has steadily climbed the heavyweight ranks, winning the 2012 Strikeforce Heavyweight Grand Prix.
He made his long awaited UFC debut on April 20, defeating former titleholder Frank Mir by unanimous decision.
Nelson (19-8) has been a fan favorite since making his way into the UFC by winning the tenth season of The Ultimate Fighter reality series. Known for his ability to absorb an incredible amount of damage and for his one-punch knockout power, Nelson knocked out Brendan Schaub and Stefan Struve in his first two fights in the UFC. He’s lost to top contenders Junior dos Santos, Fabricio Werdum and Frank Mir, but has faced the top competition inside the organization.
Prior to the fight being officially announced, the two had gotten into exchanges on Twitter. Last week, Cormier wrote up an informal bout agreement and signed it before tweeting it to Nelson. Nelson quickly inked his signature and sent it back.