Phoenix Laroche

William

Alex Lawther

Velveteen Rabbit (voice)

Samantha Colley

Mother

Leonard Buckley

Father

Tilly Vosburgh

Mary "Momo"

Helena Bonham Carter

Wise Horse (voice)

Lois Chimimba

Car (voice)

Paterson Joseph

King (voice)

Clive Rowe

Lion (voice)

Ellie Mejia

Miss Forrester

Conor Hamill

William's Friend

Paul Sparkes

Removal Man

Kiefer Moriarty

Adult at Party

Elizabeth O'Toole

Lucy

Jack Finn

Child

Declan Mills

George

Edward Baker-Duly

Doctor

Sean Duggan

Teacher

Nathaniel Parker

Male Rabbit (voice)

Bethany Antonia

Female Rabbit (voice)

Nicola Coughlan

Playroom Fairy (voice)

Ian Dillon

Church Attendee (uncredited)