Justice Smith Owen Brigette Lundy-Paine Maddy Ian Foreman Young Owen Helena Howard Isabel Lindsey Jordan Tara Danielle Deadwyler Brenda Fred Durst Frank Conner O'Malley Dave Emma Portner Amanda / Mr. Melancholy / Marco / Evil Clown Madaline Riley Polo Amber Benson Johnny Link's Mom Albert Birney Mr. Sprinkly Michael C. Maronna Neighbor 1 Danny Tamberelli Neighbor 2 Timothy Allan Lance Tyler Dean Flores Cade Elizabeth Scopel Drive-Thru Kid Marlyn Bandiero Brenda's Friend Phoebe Bridgers Phoebe Bridgers Michael Twaine Older Theatre Goer #1 (uncredited) Evangeline Johns Older Theatre Goer #2 (uncredited) Elaine Apruzzese Fun Center Patron / Carnival Patron (uncredited) Cynthia Clancy Election Day Volunteer (uncredited) Will Fitz Laser Tag Player (uncredited) Ben Heineman Teenage Kid in Movie Theater (uncredited) Julissa Piatt Kid At A Party (uncredited)