 Domhnall GleesonAlan Alexander Milne / Blue | Alan Alexander Milne / Blue |
 Margot RobbieDaphne Milne | Daphne Milne |
 Will TilstonChristopher Robin Milne / Billy Moon | Christopher Robin Milne / Billy Moon |
| SStanley HamlinChristopher Robin Milne (Baby) | Christopher Robin Milne (Baby) |
| DDexter HymanChristopher Robin Milne (Kid) | Christopher Robin Milne (Kid) |
| SSonny HymanChristopher Robin Milne (Kid) | Christopher Robin Milne (Kid) |
 Alex LawtherChristopher Robin Milne (Teen) | Christopher Robin Milne (Teen) |
 Kelly MacdonaldOlive Rand / Nou | Olive Rand / Nou |
 Phoebe Waller-BridgeMary Brown | Mary Brown |
 Vicki PepperdineBetty | Betty |
 Stephen Campbell MooreErnest H. Shepard | Ernest H. Shepard |
 Richard McCabeRupert | Rupert |
 Geraldine SomervilleLady O | Lady O |
 Nico MirallegroCooper | Cooper |
 Shaun DingwallAlfred Brockwell | Alfred Brockwell |
 Dan MacKayBob Clerkwell | Bob Clerkwell |
 Mossie SmithSharon the Midwife | Sharon the Midwife |
 Tommy RodgerDouglas Minor | Douglas Minor |
 Robert PortalHeadmaster | Headmaster |
 Allegra MarlandFan | Fan |
| NNicholas RichardsonNewspaper Man | Newspaper Man |
| JJim CartwrightMilitary Medic | Military Medic |
| VVincent FinchBig Boy | Big Boy |
 Richard CliffordToy Shop Manager | Toy Shop Manager |
 Simon ConnollyRadio Host | Radio Host |
 Richard DixonMC at Pageant | MC at Pageant |
| AAnn ThwaitePageant Dignitary | Pageant Dignitary |
 Sarah Jayne ButlerWinning Mum | Winning Mum |
 Victoria BavisterMother at Zoo | Mother at Zoo |
 Simon WilliamsZoo Director | Zoo Director |
