Vanya

Ellen Page

Luther Hargreeves / Number One

Tom Hopper

Allison Hargreeves / Number Three

Emmy Raver-Lampman

Cha-Cha

Mary J. Blige

Number Five

Aidan Gallagher

Diego

David Castaneda

Hazel

Cameron Britton

Klaus Hargreeves / Number Four

Robert Sheehan

Pogo (voice)

Adam Godley

Detective Eudora Patch

Ashley Madekwe

Ben Hargreeves / Number Six

Justin H. Min

Sir Reginald Hargreeves

Colm Feore

Lila Pitts

Ritu Arya

Leonard Peabody

John Magaro

Grace

Jordan Claire Robbins

Young Allison

Eden Cupid

The Handler

Kate Walsh

Young Luther

Cameron Brodeur

Raymond Chestnut

Yusuf Gatewood

Young Ben

Ethan Hwang*

Dr. Jean Thibedeau

Megan Mullally

Dr. Gene Thibedeau

Nick Offerman

Agnes

Sheila McCarthy

Young Vanya

T.J. McGibbon

Syd

Murray Furrow

Sissy Cooper

Marin Ireland

Sloane Hargreeves

Genesis Rodriguez

Fei Hargreeves

Britne Oldford

Herb / Pogo Body

Ken Hall

Alphonso Hargreeves

Jake Epstein

Harlan

Justin Paul Kelly

Jayme Hargreeves

Cazzie David

Axel

Kristen Holden-Ried

Otto

Jason Bryden

Young Klaus

Dante Albidone

Carl Cooper

Stephen Bogaert

Chet Rodo

Julian Richings

Young Diego

Blake Talabis

Dot

Patrice Goodman

Elliot

Kevin Rankin

Stan

Javon Walton

Detective Chuck Beaman

Rainbow Sun Francks

Super Old Five / Older Five / Old Man Five

Sean Sullivan

Oscar

Tom Sinclair

Keechie

Dov Tiefenbach

Lester Pocket

Callum Keith Rennie

Abigail Hargreeves

Liisa Repo-Martell

Claire Hargreeves

Millie Davis

Young Vanya (Age 4)

Alyssa Gervasi

Jack Ruby

John Kapelos

Young Dave

Calem MacDonald

Gruff Manager

Tony Marra

Wife / Lila's Mom

Shiva Safari

Jennifer

Victoria Marie