Elliot Page as Juno MacGuff

Michael Cera as Paulie Bleeker

Jennifer Garner as Vanessa Loring

Jason Bateman as Mark Loring

J.K. Simmons as Mac MacGuff

Allison Janney as Bren MacGuff

Olivia Thirlby as Leah

Eileen Pedde as Gerta Rauss

Rainn Wilson as Rollo

Daniel Clark as Steve Rendazo

Darla Fay as Bleeker's Mom

Aman Johal as Vijay

Valerie Tian as Su-Chin

Emily Perkins as Punk Receptionist

Kaaren de Zilva as Ultrasound Technician

Steven Christopher Parker as Guy Lab Partner

Candice King as Amanda, Girl Lab Partner

Sierra Pitkin as Liberty Bell

Cut Chemist as Chemistry Teacher

Eve Harlow as Tough Girl

Kirsten Alter as Nurse

Emily Tennant as Pretty-to-Goth Girl

Ashley Whillans as Katrina De Voort

Jeff Witzke as Track Announcer

Colin McSween as Keith

Peggy Logan as Sex Ed Teacher

Cameron Bright as RPG Nerd

Joy Galmut as Delivery Room Doctor

Wendy Russell as Vanessa's Friend #1

Robyn Ross as Vanessa's Friend #2