KJ Noons competed in boxing, kickboxing and MMA, winning the EliteXC title and later fighting in Strikeforce and the UFC. His boxing was the center of his MMA game. He stayed on his feet, worked combinations and made opponents deal with his hands before they could get to a takedown.

Noons beat Nick Diaz in EliteXC and they met again in Strikeforce, where Diaz won the rematch. He also beat Yves Edwards and Jorge Gurgel before making his UFC debut against Donald Cerrone in 2013.

Noons was part of the Metal Mulisha fight team during those Strikeforce years.