Hey Harold!

Phillip Van Dyke

Arnold (voice)

Francesca Marie Smith

Helga Pataki (voice)

Jamil Walker Smith

Gerald Johanssen (voice)

Olivia Hack

Rhonda Wellington Lloyd (voice)

Anndi McAfee

Phoebe Heyerdahl (voice)

Justin Shenkarow

Harold Berman (voice)

Dan Castellaneta

Grandpa Phil (voice)

Ben Diskin

Eugene Horowitz (voice)

Christopher Walberg

Stinky Peterson (voice)

Craig Bartlett

Brainy (voice)

David Wohl

Mr. Berman (voice)

Danielle Judovits

Patricia "Big Patty" Smith (voice)

Kath Soucie

Mrs. Berman (voice)

Sam Gifaldi

Sid / Robert (voice)