Joe Warren is an American Greco-Roman wrestler and mixed martial artist. As a Greco-Roman wrestler, he won the 2006 Pan American and World Championship and was a favourite for the 2008 Olympics. He later participated in and won the 2007 World Cup. During the end of 2008 Warren started transitioning to mixed martial arts, and on March 8, 2009, he made his professional debut. He has competed for Bellator MMA, and Dream in Japan. He is a former Bellator Bantamweight Champion and former Bellator Featherweight Champion. Warren is currently ranked as the #7 Bantamweight in the world and as the #2 Bantamweight outside of the UFC by fightmatrix.com.