"Bad Guy" (stylized in all lowercase) is a song by American singer Billie Eilish. It was released on March 29, 2019, through Darkroom and Interscope Records. The song serves as the fifth single from Eilish's debut studio album When We All Fall Asleep, Where Do We Go? (2019), as confirmed by Billboard. The music video was also released on March 29.

Billie Eilish宣布将于7月30日发行个人新单《my future》！