Klaus

Jason Schwartz...

as

Jesper (voice)

J.K. Simmons

as

Klaus (voice)

Rashida Jones

as

Alva (voice)

Joan Cusack

as

Mrs. Krum (voi...

Norm Macdonald

as

Mogens (voice)

Will Sasso

as

Mr. Ellingboe ...

Sergio Pablos

as

Pumpkin / Olaf...

Mila Brener

as

Ellingboe Girl...

Neda Margrethe...

as

Margu (voice)

Sydney Brower

as

Ellingboe Girl...

Teddy Blum

as

Small Ellingbo...

Julian Zane

as

Krum Boy (voic...

Emma Shannon

as

Creepy girl 1 ...

Kendall Joy Ha...

as

Annelise (voic...

Sky Alexis

as

Ellingboe Girl...

Tucker Meek

as

Ellingboe Boy ...

Amanda Philips...

as

Ellingboe Coun...

Finn Carr

as

Ellingboe Boy ...

Lucian Perez

as

Krum Boy / Cre...

Emma Yarovinsky

as

Little Krum Gi...

Jaeden Bettenc...

as

Krum Boy / Jes...

Hailey Hermida

as

Krum Girl 1 (v...

Evan Agos

as

Ellingboe Boy ...

Leo Miller

as

Ellinboe Boy 5...

Bailey Rae Fen...

as

Creepy Girl 2 ...

Ayden Soria

as

Creepy Boy 1 (...

Reiulf Aleksan...

as

Adult Saami (v...

Matthew McCann

as

Additional Kid...

Hudson West

as

Additional Kid...

Joaquin Obrado...

as

Boy (voice)