David Loiseau (French pronunciation: [david lwazo]; born December 17, 1979) is a Canadian mixed martial artist from Montreal, Quebec. He has fought in the Ultimate Fighting Championship, EliteXC, and TKO Major League MMA and is the former TKO Middleweight Champion. He was the first French Canadian to fight in the Ultimate Fighting Championship. He has also played a gang member in French Canadian movie La rage de l'ange.

Loiseau began his MMA career fighting for Canadian based organization UCC (later TKO organisation). He earned a record of 8-2, with notable wins over Joe Doerksen and Tony Fryklund. He has since had several stints fighting for the UFC, TKO and various other MMA organizations. His professional record is 20-10.

Loiseau made his UFC debut in April 2003 at UFC 42 where he was successful, defeating Mark Weir by KO. He returned later in the year at UFC 44 and lost a unanimous decision to Jorge Rivera. Loiseau returned to the UFC in 2005 with TKO wins of Gideon Ray, Charles McCarthy and Evan Tanner. Loiseau then lost back to back matches in 2006 via unanimous decision to Rich Franklin at UFC 58 and to Mike Swick at UFC 63. In 2009, Loiseau returned again, this time losing another unanimous decision to Ed Herman at UFC 97. Loiseau was subsequently released from the UFC following this loss.

He recently returned to the UFC only to lose again to Mario Miranda via TKO on June 12, 2010 at UFC 115 and was once again released from the UFC following this loss.

In his first fight after his UFC release, Loiseau fought Leopoldo Serao at Tachi Palace Fights 8: All or Nothing for the TPF Middleweight Championship and was victorious via TKO (Doctor Stoppage) in the fifth round becoming the TPF Middleweight Champion. Loiseau was expected to make the first defense of his TPF middleweight belt at TPF 10 on Aug. 5 against Givanildo Santana. Loiseau's Agent announced on July 28, 2011 that Loiseau sustained an undisclosed injury which would require surgery and that he would not be able to defend his title an TPF 10. Loiseau later revealed in an interview with KORE Vision that he recently underwent surgery and is training to make a comeback.