Early career Riggs made his professional mixed martial arts debut in 2001 and compiled a record of 13–3 with one no contest before being signed by the WEC.
UFC and WEC Riggs made his WEC debut at
WEC 9 against
Alex Stiebling, in what was also his debut at
Light Heavyweight. Riggs lost via triangle choke submission in the second round. But after the fight people started to take notice of Riggs. Although he lost the fight, he battered Stiebling so badly that after the fight he had to be helped out of the cage and taken to a hospital. Reports said that almost everyone at ring side had Stiebling's blood on both them and their paperwork. The promoter Scott Adams said the fight could and should have been stopped at several points in the fight, leading it to be known as one of the most brutal fights in WEC history. After that he went down to middle weight to fight Isidro Gonzalez in the WEC. Where Riggs finished the fight early in the 1st Round by TKO. After his impressive victory over Gonzalez the WEC gave him a shot at the vacant Middleweight Title against the undefeated Rob Kimmons. Riggs put on a very impressive performance by stopping Kimmons early in the 1st round, earning him the WEC world title, which he held for the next 2 years. Riggs' dream of fighting in the UFC materialized in 2004, in a winning bout against Canadian fighter
Joe Doerksen. After that Riggs moved down to Welterweight to fight veteran
Chris Lytle. Riggs went on to win the fight by 2nd-round TKO. And was the 1st and only man to ever stop the very popular battler Chris Lytle. Then after being named the UFCs number 1 Welter Weight contender. Riggs received his shot at the
UFC Welterweight Championship at
UFC 56 in November 2005 against
Matt Hughes. He was originally supposed to face the winner of the upcoming title fight. But got called to fight just a month after the defeating Lytle in UFC 55 to face long time champion Hughes for the UFC Welter Weight title. Originally, the title shot was offered to
Karo Parisyan, who had to withdraw due to a torn
hamstring. When Riggs was contacted to take Parisyan's place he jumped at the chance, despite having fought at
UFC 55 just a month earlier. However, Riggs did not make the required weight and the fight was declared a non-title event, due to Hughes allowing Riggs to fight him (if a fighter does not make weight for a match, the match may still take place if their opponent allows it). Despite his efforts, Riggs could not mount a significant challenge; Hughes took him down and submitted him with a
kimura from
half-guard just minutes into the first round of the fight. Following his loss to Hughes, Riggs rebounded to win against future longtime
Strikeforce Welterweight Champion,
Nick Diaz via decision at
UFC 57. In the hospital room after the fight, Diaz and Riggs got into a physical altercation where they had to be separated by
police. Riggs then moved up to
Middleweight to face
The Ultimate Fighter alumnus
Mike Swick. Early in the fight Riggs was caught in a
guillotine choke and tapped out. Riggs then fought ''
The Ultimate Fighter 2's''
Jason Von Flue, submitting him with a
triangle choke. Riggs' last UFC bout was on December 13, 2006, against Welterweight contender
Diego Sanchez at
UFC Fight Night 7. Riggs lost the fight due to knockout from a hook followed by a knee in 1:45 of the first round. Following the fight with Sanchez, Riggs chose to go to the WEC and compete for the vacant
WEC Middleweight Championship, but had to pull out of the fight the day before because of a recurring back injury.
Strikeforce Riggs lost to Cory Devela via submission in his Strikeforce debut at
Strikeforce: At The Dome. Riggs was to return to action on
Strikeforce: Melendez vs. Thomson, facing
Jiujitsu specialist Luke Stewart. Riggs stepped in as a late replacement for
Shonie Carter, who was injured in training. The fight was to be contested at a catchweight of 178 pounds. However, he was denied licensure by the
California State Athletic Commission after disclosing his recent use of prescription medication during the licensing process. Riggs lost to
Kazuo Misaki at Strikeforce at the Playboy Mansion via controversial stoppage on September 20, 2008. Riggs won his next fight at
Strikeforce: Destruction on November 21, 2008, against Luke Stewart by TKO (Punches) in 2nd round 2:05. Riggs broke his hand throwing the first punch of the bout, but managed to rally in the second round, breaking Stewart's nose in the process. Riggs next fought on the
Strikeforce: Lawler vs. Shields card from the
Scottrade Center in St. Louis, MO on June 6, 2009, against
Phil "The New York Badass" Baroni in a three-round welterweight bout that won him the interim Strike Force Welter Weight title and that was broadcast live on the Showtime cable network. In a performance that featured his versatile standup game, including several flying knees, Riggs won a unanimous decision over Baroni. In his next fight, Riggs faced
Jay Hieron on January 30, 2010, at
Strikeforce: Miami.
Bellator About a month later, on January 10, 2011, Riggs signed with
Bellator to fight in its Middleweight division. Riggs made his Bellator debut against Season 2 Middleweight Tournament Finalist
Bryan Baker at
Bellator 43. After a back and forth fight, Baker knocked Riggs out with a left hook late in the second round.
Independent promotions Three months after his knockout loss to Baker at
Bellator 43, In a rematch from their bout in 2004 Riggs fought
The Ultimate Fighter 3 winner and fellow UFC veteran
Kendall Grove. Grove quickly defeated Riggs by submission due to a guillotine choke, Thus avenging his previous loss to Riggs. For the first time in his ten-year career as a mixed martial artist Riggs has lost three straight fights. After the loss to Grove he went on a five-fight win streak.
Fight Master: Bellator MMA On May 6, 2013, it was announced that Riggs would be featured as a participant on
Bellator's reality TV show
Fight Master: Bellator MMA, competing as a Welterweight. In his first fight to get into the house, Riggs defeated UK fighter Rob Mills via heel hook submission in the first round and subsequently chose to join
Greg Jackson's team. In the preliminary round, Riggs defeated Eric Scallan via unanimous decision and went on to the quarterfinal round where he defeated Evan Cutts via unanimous decision. In the semifinal round, Riggs defeated number one seed Cole Williams in a three-round split decision victory. He made it to the tournament finals with
Mike Bronzoulis. Riggs was set to face
Mike Bronzoulis in the
Fight Master Finale on September 7, 2013, at
Bellator 98. However, on September 3, it was revealed Riggs has sustained a significant eye injury and the bout was postponed indefinitely. The bout took place on November 2, 2013, at
Bellator 106. Riggs won the fight via unanimous decision to become the first winner of Fight Master.
Return to UFC After becoming the first winner of Fight Master, Riggs was expected to return to UFC and face
Paulo Thiago at
UFC Fight Night 51 on September 13, 2014, replacing an injured Mike Rhodes. However, Riggs was forced to pull out of the fight after accidentally shooting himself in the hand and leg while cleaning a pistol at his home. Riggs made his eventual return against
Ben Saunders at
UFC on Fox: dos Santos vs. Miocic on December 13, 2014, at
US Airways Center in Phoenix, Arizona. The fight ended early in the first round by TKO due to injury when Riggs hurt his neck on a take down and tapped out shortly thereafter. Joe Riggs faced
Patrick Côté on April 25, 2015, at
UFC 186. Riggs lost the back-and-forth fight by unanimous decision. Riggs was expected to face
Uriah Hall in a middleweight bout on August 8, 2015, at
UFC Fight Night 73. However, Riggs pulled out of the fight in late July, citing an injury, and was replaced by promotional newcomer
Oluwale Bamgbose. Following a quick recovery, Riggs faced
Ron Stallings on September 5, 2015, at
UFC 191. Riggs won the bout via disqualification after Stallings landed an illegal upkick, which rendered Riggs unable to continue. Riggs faced
Chris Camozzi on February 21, 2016, at
UFC Fight Night 83. He lost the fight via TKO in the first round due a series of knees by Camozzi, which broke the right forearm of Riggs. On April 13, Riggs was released from the promotion.
Post UFC In his first bout post his second UFC release, Riggs achieved a catchweight victory over
Cody McKenzie in Medicine Hat, Alberta, Canada. They continued their winning streak with victories over Billy Martin, Jerome Jones, Dmitry Samoilov, and
Shonie Carter, ultimately winning the vacant Fight Night Light Heavyweight Championship on September 9, 2017. Riggs then went on to win against Oleg Olenichev and Erick Lozano, securing the KOP Middleweight Championship on February 24, 2018. After a draw against Borys Polezhai, Riggs faced a loss against Artem Frolov on June 1, 2018, for the M-1 Middleweight Championship. The fighter bounced back with a win over Dan Yates on January 4, 2019, before their most recent fight against
George Sullivan was overturned due to a positive test for PEDs. ==Bare-knuckle boxing==