Jodie Comer as Isla

Alfie Williams as Spike

Aaron Taylor-Johnson as Jamie

Ralph Fiennes as Dr. Ian Kelson

Edvin Ryding as Erik Sundqvist

Christopher Fulford as Sam

Stella Gonet as Jenny

Chi Lewis-Parry as Samson

Jack O'Connell as Jimmy Crystal

Rocco Haynes as Young Jimmy

Kim Allan as Jimmy's Mother

Sandy Batchelor as Jimmy’s Father

Amy Cameron as Rosey

Geoffrey Newland as Anthony

Joe Blakemore as Dave

Celi Crossland as Pregnant Infected

Robert Rhodes as Jimmy Jimmy

Erin Kellyman as Jimmy Ink

Sam Locke as Jimmy Fox

Maura Bird as Jimmy Jones

Ghazi Al Ruffai as Jimmy Snake

Emma Laird as Jimmima

Connor Newall as Jimmy Shite

Sienna Giblin as Girl Villager

Hayley Walters as Teenage Girl Villager

Peter Labas as Slow Low #1

Kat Kitchener as Slow Low #2

Jason Kuang Yao Lee as Slow Low #3

Ember Storm as Slow Low #4

Jake Grimes as Hanging Man

Chris Gregory as Berserker

Helen Rowlands as Infected Woman

Haley Flaherty as Jimmy's Auntie

Harriet Taylor as Jimmy's Cousin Delilah

Hannah Allan-Robertson as Jimmy's Sister

Annabelle Graham as Jimmy's Sister

Olivia Morley as Jimmy's Sister

Theadora Rawlings as Jimmy's Sister

Darcie Smith as Jimmy's Sister

Isla Vickers as Jimmy's Sister

Lachlan Tucker as Baby Isla

Winnow Short as Baby Isla

Olivia Grace Lee as Baby Isla

Lucas Toole as Baby Isla

Cohen Lewis Williamson as Baby Isla

Myles Woodhouse as Baby Isla

Gordon Alexander as Jonno (uncredited)

Angus Neill as Emaciated Infected (uncredited)

Col Needham as Dead Body #6 (Uncredited)

RuMac as Accordionist (uncredited)