Kamen Rider 0 (仮面ライダー０号, Kamen Raidā Reigō) was an unused Kamen Rider from Kamen Rider created by producer Tohru Hirayama. He is a prototype of Kamen Rider 1 made by Professor Midorikawa, however, his surgery was unsuccessful and killed him immediately.

Hirayama's colleagues and successors used the title "Kamen Rider 0" to code their various "reboot" projects during the Showa era continually.

•Skyrider
•Kamen Rider Black
•Kamen Rider Shin

(A/N: New Kamen Rider as "Kamen Rider 0". Illustrated by Shotaro Ishinomori.)

(A/N: Batta Man as "Kamen Rider 0". Illustrated by Shotaro Ishinomori.)