The rapper was in a car yesterday on Chicago's South Side when an unidentified assailant approached and shot him in the head, police said.
It was unclear the extent of his injuries but the Chicago Sun-Times quoted a member of his management saying the rapper was "awake and talking."
Soon after the shooting, King Louie's Instagram account showed a picture of him with three children in front of a Christmas tree as he promised to care for them "as long as I'm living."
Drill music takes the hard-driving beats of trap -- a type of hip-hop originating in the Southern United States -- but brings in especially dark lyrical content about street life.
King Louie was tapped by Chicago-bred rap superstar Kanye West for his drill-influenced album "Yeezus," with their politically charged collaboration "New Slaves" nominated for the 2014 Grammy for Best Rap Song.
Director Spike Lee recently released a film entitled "Chi-Raq" that satirizes gang violence in Chicago using elements of classic Greek comedy.
The film by New York-based Lee has upset some in Chicago, with politicians urging him to change the name and one of the city's leading hip-hop artists, Chance The Rapper, calling it exploitative.
Chance The Rapper voiced hope for King Louie's recovery, tweeting: "Send prayers to him in his battle.
