Nat Wolff

Quentin

Cara Delevingne

Margo

Austin Abrams

Ben

Justice Smith

Radar

Halston Sage

Lacey

Jaz Sinclair

Angela

Cara Buono

Mrs. Jacobsen

Hannah Riley

Young Margo

Meg Crosbie

Ruthie

Griffin Freeman

Jase

Caitlin Carver

Becca

Susan Macke Miller

Mrs. Spiegelman

Tom Hillmann

Mr. Spiegelman

Stevie Ray Dallimore

Mr. Jacobsen

Jay Duplass

English Teacher

Drew Matthews

Gus

Jim R. Coleman

Detective Warren

Ansel Elgort

Mason (uncredited)

John Green

Becca's Father (voice) (uncredited)