Damien Chazelle Director Ryan Gosling Sebastian Actor Emma Stone Mia Actor John Legend Keith Actor, Executive Producer Rosemarie DeWitt Laura Actor J.K. Simmons Boss Actor Finn Wittrock Greg Actor Meagen Fay Mia's Mom Actor Callie Hernandez Tracy Actor Sonoya Mizuno Caitlin Actor Jessica Rothe Alexis Actor Tom Everett Scott David Actor Josh Pence Josh Actor Mike Jackson Executive Producer Qiuyun Long Executive Producer Thad Luckinbill Executive Producer Fred Berger Producer Jordan Horowitz Producer Marc Platt Producer Gary Gilbert Producer Linus Sandgren Cinematographer Tom Cross Film Editing Justin Hurwitz Original Music David Wasco Production Design Austin Gorg Art Director Sandy Reynolds-Wasco Set Decoration Mary Zophres Costume Design Deborah Aquila Casting Mary Tricia Wood Casting