Aidan Gallagher
Number Five

Elliot Page
Vanya Hargreeves / Number Seven / Viktor Hargreeves / Number Seven

Tom Hopper
Luther Hargreeves / Number One

Emmy Raver-Lampman
Allison Hargreeves / Number Three

Robert Sheehan
Klaus Hargreeves / Number Four

David Castañeda
Diego Hargreeves / Number Two

Justin H. Min
Ben Hargreeves / Number Six

Colm Feore
Sir Reginald Hargreeves

Ritu Arya
Lila Pitts

Jordan Claire Robbins
Grace

Adam Godley
Pogo (voice)

Kate Walsh
The Handler

Yusuf Gatewood
Raymond Chestnut

Cameron Britton
Hazel

Sheila McCarthy
Agnes

Marin Ireland
Sissy Cooper

Ken Hall
Herb / Pogo Body / Herb / Pogo Body

Mary J. Blige
Cha-Cha

Genesis Rodriguez
Sloane Hargreeves

John Magaro
Leonard Peabody