Joe "Mongo" Williams is an American Welterweight fighter who is currently signed to Bellator. He has previously competed in King of the Cage and obtained the Respect in the Cage Middleweight championship a little more than three months into his professional career. He has finished all but two of his wins and his only loss came in his Bellator debut. He has an extensive wrestling background. Joe began wrestling at age eight and has since captured multiple state and national championships and even wrestled for Michigan State University. He decided to begin competing in MMA at the insistence of the manager of a friend who he was teaching wrestling to for MMA.

After losing his Bellator debut by decision to Andy Uhrich, Williams bounced back with a first round suits silk of Rod Montoya only forty-one days later. Wiliams then defeated Jamie Yager at Bellator 85.

Joe Williams competed on Fight Master: Bellator MMA, but was defeated in the preliminary round by Cole Williams.  However, following Andy Uhrich's preliminary bout, it was found Uhrich could not continue due to a deep cut over his eye.  "Mongo" was given another shot in the competition, taking Uhrich's spot on Frank Shamrock's team.  Due to not winning his preliminary bout, Williams was seeded at #16 out of 16 in the tournament's elimination round.  A win over #12 ranked Ismael Gonzalez did little for Williams' ranking as he was at #7 out of 8 for the quarterfinal round, losing to #6 ranked Eric Bradley.

Fight Master: Bellator MMA

Episode 2 Cole Williams def. Williams by Unanimous Decision

Episode 5 Williams def. Ismael Gonzalez by Submission (arm-triangle choke) in Round 2

Episode 9 Eric Bradley def. Williams by Unanimous Decision