Vanya
Ellen Page
Number Five
Aidan Gallagher
Luther Hargreeves / Number One
Tom Hopper
Hazel
Cameron Britton
Young Allison
Eden Cupid
Diego Hargreeves / Number Two
David Castañeda
Allison
Emmy Raver-Lampman
Young Luther
Cameron Brodeur
Young Ben
Ethan Hwang*
Klaus
Robert Sheehan
Ben Hargreeves
Justin H. Min
Sir Reginald Hargreeves
Colm Feore
The Handler
Kate Walsh
Lila Pitts
Ritu Arya
Pogo (voice)
Adam Godley
Young Vanya
T.J. McGibbon
Grace
Jordan Claire Robbins
Raymond Chestnut
Yusuf Gatewood
Sissy
Marin Ireland
Cha-Cha
Mary J. Blige
Syd
Murray Furrow
Agnes
Sheila McCarthy
Detective Eudora Patch
Ashley Madekwe
Leonard Peabody
John Magaro
Herb / Pogo Body
Ken Hall
Sloane Hargreeves
Génesis Rodríguez
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
Fei Hargreeves
Britne Oldford
Stan
Javon Walton
Detective Chuck Beaman
Rainbow Sun Francks
Older Five / Super Old Five / Middle Aged 5
Sean Sullivan
Oscar
Tom Sinclair
Keechie
Dov Tiefenbach
Lester Pocket
Callum Keith Rennie
Abigail Hargreeves
Liisa Repo-Martell
Dr. Gene Thibedeau
Nick Offerman
Dr. Jean Thibedeau
Megan Mullally
Claire Hargreeves
Millie Davis
Young Vanya (Age 4)
Alyssa Gervasi
Jack Ruby
John Kapelos
Young Dave
Calem MacDonald
Gruff Manager
Tony Marra
Alphonso Hargreeves
Jake Epstein
Jayme Hargreeves
Cazzie David
Wife / Lila's Mom
Shiva Safari
Jennifer
Victoria Marie