Cailey Fleming as Bea

Ryan Reynolds as Cal

John Krasinski as Dad / Marshmallow (voice)

Fiona Shaw as Grandmother

Steve Carell as Blue (voice)

Phoebe Waller-Bridge as Blossom (voice)

Louis Gossett Jr. as Lewis (voice)

Alan Kim as Benjamin

Liza Colón-Zayas as Janet

Bobby Moynihan as Jeremy

Catharine Daddario as Bea’s Mom

Audrey Hoffman as Bea (Ages 3 & 5)

Laquet Sharnell Pringle as Receptionist

Ed Herbstman as Deli Guy

Barbara Andres as Woman Upstairs

Alexander Rivero as Custodian

Shauna Pinkett as Hospital Receptionist

Sa'Raya Paris Johnson as 7 Year-Old Girl

Marta Siteiya Moipei as Coffee Shop Barista

David Weissmann as Young Jeremy

Awkwafina as Bubble (voice)

Emily Blunt as Unicorn (voice)

George Clooney as Spaceman (voice)

Bradley Cooper as Ice (voice)

Matt Damon as Flower (voice)

Bill Hader as Banana (voice)

Richard Jenkins as Art Teacher (voice)

Keegan-Michael Key as Slime (voice)

Blake Lively as Octopuss (voice)

Sebastian Maniscalco as Magician Mouse (voice)

Christopher Meloni as Cosmo (voice)

Matthew Rhys as Ghost (voice)

Sam Rockwell as Guardian Dog (voice)

Maya Rudolph as Alligator (voice)

Amy Schumer as Gummy Bear (voice)

Allyson Seeger as Viola (voice)

Jon Stewart as Robot (voice)

Craig 'Radio Man' Castaldo as Radio Man (uncredited)

José Garcia as (voice) (uncredited)

Mylène Farmer as (voice) (uncredited)

Marina Foïs as (voice) (uncredited)

Clément Remiens as (voice) (uncredited)