Astro Boy is the main protagonist of the whole franchise.
- Mari Shimizu - Japanese (1963/1980)
- Mary Lou Foster - English (1963; Pilot Only)
- Billie Lou Watt - English (1963)
- Patricia Kugler Whitely - English (1980; American)
- Steven Bednarski - English (1980; Canadian)
- Makoto Tsumara - Japanese (2003)
- Candi Milo - English (2003)
- Freddie Highmore - English (2009)
- Aya Ueto - Japanese (2009)
He is the faithful assistant to Reni.
He plays Genie in Cobaltladdin (1992), Cobaltladdin 2: The Return of Megatron, Cobaltladdin (TV Series), and Cobaltladdin 3: The King of Thieves.
He is a Genie.
He plays Young Simba in The Autobot King (1994).
He is a lion cub.
He plays Rudolph in Atom the Red-Nosed Robot (1964), Atom's Shiny New Year, and Atom and Modo's Christmas in July.
He plays Mowgli in The Mastiff Book version 2
He is a man-cub.
He plays Aladdin in Astroladdin, Astroladdin II: The Return of Captain Hook and Astroladdin III: The King of Thieves
He is a street rat.
He plays Casper in Astro Boy (Casper)
He's the friendliest ghost.
He plays Yao in Sakuralan and Sakuralan II
He is a soldier in the chinese army.
He plays Jake Long in American Robot: Toby Tenma/Astro Boy
He is a japanese boy.
He plays Kuzco (Human) in The Robot Boy's New Groove, The Robot Boy's New Groove 2: Flint's New Groove and The Robot Boy's New School
He is an emperor.