Domhnall Gleeson as Alan Alexander Milne / Blue

Margot Robbie as Daphne Milne

Will Tilston as Christopher Robin Milne / Billy Moon

Stanley Hamlin as Christopher Robin Milne (Baby)

Dexter Hyman as Christopher Robin Milne (Kid)

Sonny Hyman as Christopher Robin Milne (Kid)

Alex Lawther as Christopher Robin Milne (Teen)

Kelly Macdonald as Olive Rand / Nou

Phoebe Waller-Bridge as Mary Brown

Vicki Pepperdine as Betty

Stephen Campbell Moore as Ernest H. Shepard

Richard McCabe as Rupert

Geraldine Somerville as Lady O

Nico Mirallegro as Cooper

Shaun Dingwall as Alfred Brockwell

Dan MacKay as Bob Clerkwell

Mossie Smith as Sharon the Midwife

Tommy Rodger as Douglas Minor

Robert Portal as Headmaster

Allegra Marland as Fan

Nicholas Richardson as Newspaper Man

Jim Cartwright as Military Medic

Vincent Finch as Big Boy

Richard Clifford as Toy Shop Manager

Simon Connolly as Radio Host

Richard Dixon as MC at Pageant

Ann Thwaite as Pageant Dignitary

Sarah Jayne Butler as Winning Mum

Victoria Bavister as Mother at Zoo

Simon Williams as Zoo Director

Nick Blakeley as Zoo Photographer

Mark Tandy as Portrait Photographer

Sam Barnes as The Times Photographer

Kevin Millington as American Man

Bentley Kalu as American Police

Rolan Bell as American Police

Mark McKerracher as Groupie

Amber Batty as Groupie

Lance C. Fuller as Groupie

Grace Curtis as McGovern Sister

Matilda Curtis as McGovern Sister

Cameron Lane as Kid

Phoebe Lyons as Kid

Harper Gray as Kid

Kirk Bowett as Limbless Veteran Soup Kitchen

Jon E Cassell as Zoo Keeper

David J Biscoe as Train Passenger

John McHale as Milne's Gardener

Talia Ray as Maid of Mallord Street

Robbie Young as School Bully

Simon Maroulis as New York Book Fan

Christopher McMullen as Homeless Man

Ashley Hudson as Young Gentleman

Jason Matthewson as Theatre Patron

Adam Lazarus as Theatre Goer

Nick Davison as Pageant WW1 Soldier

Matthew Di Liello as WW1 Soldier

David Evestaff as WW1 Soldier

Bernardo Santos as WW1 Soldier

Kirk Bowett as Wounded Soldier

Gintare Beinoraviciute as Party Guest

Tom Dab as Party Guest

Emma Caraman as Party Guest

Callum Forman as Party Guest

Gemma Wilks as Party Guest

Honey Holmes as Party Guest

Jamie Body as Bright Young Thing

Sean Moon as Bright Young Thing

Elisa Hayrapetyan as Waltz Dancer

Beatrice Stein as Dancer

Tamsin Ella Harding as Dancer

Iulia Filipovscaia as Dancer

Ceri Jerome as Dancer