Justin Robert Levens (April 18, 1980 - December 17, 2008) was an American professional mixed martial arts (MMA) fighter who fought for the Southern California Condors of the International Fight League. Levens was a participant in Ultimate Fighting Championship and World Extreme Cagefighting but has not fought with either since 2006. Levens and his wife died from gunshot wounds in mid-December 2008.

The circumstances of their deaths remain under investigation, but the incident is believed to have been a murder-suicide, according to law enforcement officials.

Levens grew up poor in Philadelphia housing projects and was on his own from age 15. He eventually moved to Newport Beach, California, where he learned to channel his aggressive energy into organized fighting. He began training at Marco Ruas' Vale Tudo academy in Orange County, and became a light heavyweight mixed martial arts fighter. Levens fought from 2004 to 2008, taking the nickname "Executioner". Levens' first fight was a victory against Hector Carrilo in 2004. He had a string of wins after the Carrilo fight for almost two years. After his seventh win, he lost to Scott Smith in January 2006. He had a declining record for the remainder of his career, interspersed with a pair of back-to-back victories against Justin Hawes and Brian Warren in fall 2006.

His last fight was scheduled for July 2008, but did not occur due to time constraints that led to scheduling issues. Levens had tested positive for oxymorphone before the fight and was suspended until January 2009. Friend Tom Atencio said Levens was troubled by his declining career. Kimbo Luzano, another friend, said Levens may have been depressed about not being able to fight and money issues, as well as troubled by the suicide of fellow MMA fighter and friend Jeremy Williams.

On December 17, 2008, Levens and his wife, Sarah McLean-Levens, 25, were found dead in their home in Laguna Niguel, California. Both had died of gunshot wounds; in Levens' case, to his head. The police are investigating the deaths as a possible murder-suicide. No suicide note was found, but a handgun was found close to Leven's body. There were no signs of a struggle.