James Corden as Peter Rabbit (voice)

Rose Byrne as Beatrix 'Bea' Potter / Jemima Puddle-Duck (voice)

Domhnall Gleeson as Thomas McGregor / Mr. Jeremy Fisher (voice)

Margot Robbie as Flopsy Rabbit / Narrator (voice)

Elizabeth Debicki as Mopsy Rabbit (voice)

Daisy Ridley as Cottontail Rabbit (voice)

Colin Moody as Benjamin Bunny (voice)

Sam Neill as Mr. McGregor / Tommy Brock (voice)

Marianne Jean-Baptiste as Harrods General Manager

Felix Williamson as Derek

Sia as Mrs. Tiggy-Winkle (voice)

Fayssal Bazzi as Mr. Tod (voice)

Ewen Leslie as Pigling Bland (voice)

Christian Gazal as Felix D'eer (voice)

Rachel Ward as Josephine Rabbit (voice)

Bryan Brown as Mr. Rabbit (voice)

David Wenham as Johnny Town-Mouse (voice)

Will Reichelt as JW Rooster II (voice)

Ming-Zhu Hii as Sarabeth

Lance Kerfuffle as J. David Scarfington

Natalie Dew as Janelle

Terenia Edwards as Siobhan

Vauxhall Jermaine as Harrods Security

Tom Greaves as Harrods Security

Sacha Horler as Betty

Alex Blias as Phil

Dave Lawson as Chris

Sam Haft as Postman

Jessica Friedman as Singing Sparrow (voice)

Shana Halligan as Singing Sparrow (voice)

Katharine Hoye as Singing Sparrow (voice)

Chris Mann as Singing Sparrow (voice)

Chad Reisser as Singing Sparrow (voice)

Fletcher Sheridan as Singing Sparrow (voice)

Alexandra Gluck as London Street Rat (voice)

Taryn Gluck as London Street Rat (voice)

Grant Crookes as Passerby (uncredited)

Gareth Davies as Bannerman

Karl Farrer as Train Commuter (uncredited)

Philippe Lacheau as (voice) (uncredited)

Élodie Fontan as (voice) (uncredited)

Julien Arruti as (voice) (uncredited)