Cast[]
- Arthur as Olie
- D.W. as Zowie
- Arthur's Mom as Olie's Mom
- Arthur's Dad as Olie's Dad
- Grandpa Dave as Pappy
- Pal as Spot
- Buster as Billy
- Kate as Binky
- Buster's Dad as Billy's Dad
- Buster's Mom as Billy's Mom
- Francine as Pollie Pi
- Binky as Screwy
- Brain as Wheelie
- Mr. Ratburn as Uncle Gizmo
- Rattles as Gloomius Maximus
- Grandma Thora as Polie Anna
- Baby Arthur as Spaceboy
- Baby Buster as Spacedog
- Ed Crossward as Little Green Dad
- George as Little Green Olie
- Tommy Tibbles as Willy Jollie
- Timmy Tibbles as Wally Jollie
Voice Cast[]
- Cole Caplan as Arthur
- Kristen Bone as D.W.
- Catherine Disher as Arthur's Mom
- Adrian Truss as Arthur's Dad/Mr. Ratburn
- Len Carlson as Grandpa Dave
- Robert Smith as Pal/Baby Buster
- Joshua Tucci as Buster
- Sunday Muse as Kate
- Philip Williams as Binky's Dad
- Ellen Ray Hennessy as Binky's Mom
- Rebecca Brenner as Francine
- Noah Reid as Binky
- Ali Mukaddam as Brain
- James Woods as Rattles
- Tedde Moore as Grandma Thora
- Kyle Fairlie as Baby Arthur
- Richard Binsley as Ed Crossward
- Jake Goldsbie as George
- Paul Haddad as Tommy Tibbles
- Juan Chioran as Timmy Tibbles