Hey Arnold!

Francesca Marie Smith
Helga Pataki (voice)

Jamil Walker Smith
Gerald Johanssen (voice)

Dan Castellaneta
Grandpa Phil (voice) / Grandpa Phil / Grandpa Phil's Father / Jolly Olly Man (vo...

Justin Shenkarow
Harold Berman (voice) / Harold Berman(voice) / Joey (voice) / Harold Berman (voi...

Anndi McAfee
Phoebe Heyerdahl (voice) / Phoebe Heyerdahl / Worker #2 (voice) / Phoebe Heyerda...

Christopher Walberg
Stinky Peterson (voice) / Stinky Peterson / Kyle (voice) / Stinky Peterson (voic...

Phillip Van Dyke
Arnold (voice) / Ludwig (voice)

Spencer Klein
Arnold (voice)

Olivia Hack
Rhonda Wellington Lloyd (voice) / Rhonda Wellington Lloyd / Mary (voice)

Lane Toran
Arnold (voice) / Wolfgang (voice) / Arnold (singing voice) / Wolfgang / French B...

Sam Gifaldi
Sid (voice) / Sid / Robert (voice) / Billy (voice)

Blake McIver Ewing
Eugene Horowitz (voice)

Tress MacNeille
Grandma Gertie (voice) / Miss Slovak (voice) / Grandma Gertie / Harold's Aunt (v...

Kath Soucie
Miriam Pataki (voice) / Mrs. Berman (voice) / Cecile (voice) / Mrs. Vitello (voi...

Maurice LaMarche
Big Bob Pataki (voice) / Big Bob Pataki / Douglas Cain (voice) / Big Bob Pataki ...

Dom Irrera
Ernie Potts (voice) / Stinky's Father (voice) / Ernie Potts / Old Man (voice) / ...

Dan Butler
Mr. Simmons (voice) / Mr. Simmons (voice; uncredited) / Mr. Simmons / Scientist ...

David Wohl
Principal Wartz (voice) / Mr. Berman (voice) / Principal Wartz / Announcer (voic...

Ben Diskin
Eugene Horowitz (voice) / Eugene Horowitz / Kid (voice)

Baoan Coleman
Mr. Hyunh (voice) / Oskar Kokoshka (voice)