Domhnall Gleeson
as Tim Lake

Rachel McAdams
as Mary

Bill Nighy
as Dad

Tom Hollander
as Harry

Margot Robbie
as Charlotte

Lydia Wilson
as Kit Kat

Lindsay Duncan
as Mum

Richard Cordery
as Uncle D

Joshua McGuire
as Rory

Will Merrick
as Jay

Vanessa Kirby
as Joanna

Tom Hughes
as Jimmy Kincade

Clemmie Dugdale
as Ginger Jenny

Harry Hadden-Paton
as Rupert

Mitchell Mullen
as Mary's Father, Fitz

Lisa Eichhorn
as Mary's Mother, Jean

Jenny Rainsford
as Polly

Natasha Powell
as Aunty May

Mark Healy
as Dans le Noir Maître D'

Ben Benson
as Theatre Deserter

Philip Voss
as Theatre Judge

Tom Godwin
as Prompter

Pal Aron
as Bhattie QC

Catherine Steadman
as Tina

Andrew Martin Yates
as Wedding Priest

Charlie Barnes
as Posy (Newborn)

Verity Fullerton
as Posy (6 Months)

Veronica Owings
as Posy (1 Year)

Olivia Konten
as Posy (2 1 / 2 - 3 Years)

Sarah Heller
as Posy (5 Years)

Jaiden Dervish
as Boy Posy

Jacob Francis
as Jeff (Newborn)

Jago Freud
as Jeff (5 Months)

Ollie Phillips
as Jeff (2 Years)

Sophie Pond
as Jo (6 Months)

Sophie Brown
as Jo - 1 Year

Molly Seymour
as Trudy (Party Guest)

Matilda Sturridge
as Flirty Girl

Tom Stourton
as John

Rebecca Chew
as Pret a Manger Server

Jon West
as Court Clerk

Graham Richard Howgego
as Judge

Kerrie Liane Studholme
as Jury Foreman

Kenneth Hazeldine
as Defendant

Barbar Gough
as Jazz Singer

Jon Boden
as Busker

Charlie Curtis
as Young Tim

Richard Griffiths
as Lawyer in Play (uncredited)

Richard E. Grant
as Lawyer in Play (uncredited)

Haruka Abe
as Japanese Girl (uncredited)

Lee Nicholas Harris
as Police Officer (uncredited)

Matthew C. Martino
as Commuter (uncredited)

Tom Coulston
as Theatre Attendee (uncredited)