Sexion d'Assaut (French pronunciation: [sɛksjɔ̃ daso]), formerly known as 3ème Prototype (for "Troisième Prototype" [tʁwɑzjɛm pʁɔtɔtip]), was a French hip hop band formed in 2002, composed of eight Parisian rappers. They are signed to independent record label Wati B, which is under exclusive license to Sony Music Entertainment France.

The founding members were L.I.O. Black M, Maska and Lefa. In 2003, it became a collective as Maître Gims and JR O Crom joined in. Throughout its existence, it included about 20 rappers, but set-up changed from time to time. The group distinguishes itself of staying away from "bling bling" that other French rappers have adopted. They also retain the style of old school hip-hop, but keep underground influences and spent almost a decade fostering an underground fanbase before releasing their debut studio album L'École des points vitaux in 2010.

Their album L'École des points vitaux in 2010 went quadruple platinum. The album En attendant L'Apogée: les Chroniques du 75 in 2011 and L'Apogée in 2012 both went platinum and diamond respectively.

The group planned to reform in 2020 with a third album, Le Retour des Rois, and a national tour planned for 2021. But the album was cancelled despite the tour taking place.