Cast of Dexter's Laboratory

Christine Cavanaugh voices Dexter, the young boy-genius with a secret laboratory in his house.

Candi Milo also voices Dexter, taking over the role from Christine Cavanaugh in later episodes.

Allison Moore voices Dee Dee, Dexter's energetic and often annoying older sister who loves to disrupt his experiments.

Kat Cressida also provides the voice for Dee Dee in later episodes of the show.

Jeff Bennett voices Dad, Dexter and Dee Dee's clueless yet loving father.

Kath Soucie voices Mom, Dexter and Dee Dee's caring and oblivious mother.

Eddie Deezen voices Mandark, Dexter's rival and fellow boy-genius who is constantly trying to outdo him.

Jennifer Hale is in the show.

Kevin Michael Richardson is in the show.

Tom Kenny is in the show.

Randy Savage voices Rasslor, a character who appears in the episode 'Rasslor'.

Dom DeLuise voices Koosalagoopagoop, an imaginary friend of Dee Dee's.