"Heroine" is a song recorded by South Korean singer Sunmi. It was released on January 18, 2018, by Makeus Entertainment and The Black Label and distributed by LOEN Entertainment, with its music video premiering the same day. The single was also featured on her 2018 EP "Warning".
Following the success of her third solo release "Gashina", which articulated a cynical attitude in the aftermath of a breakup, Sunmi conceptualized "Heroine" as a prequel narrative to it. She drew inspiration from the Adrian Lyne film 9½ Weeks (1986), expressing a "show must go on" sentiment as the protagonist deals with a turbulent relationship.