Dr. Hell is a name used by the main villain involving series that included different versions of the Mazinger Z.
- Dr. Hell (Manga): The main villain of the original manga and archenemy of the Kabuto family.
- Dr. Hell (TV): The leader of an army composed of cyborgs and giant Mechanical Beasts.
- God Kaiser Hell: A martian warlord who opened the gates of Hell and made an army of cyborg demons.
- Dr. Hell (Z Mazinger): A servant of Hades who spearheads the army of Mechanical Beasts.
- Dr. Hell (Kaiser): The finder of the Mechanical Beasts and later Ghost Mechanical Beasts who leads his assault against the Kaiser.
- Dr. Hell (Angels): The main villain who distributes Mechanical Beasts to criminals before taking action himself.
- Dr. Hell (Shin): The former teacher of Tsubasa and user of the ancient technology of Mycenae.
- Dr. Hell (ZERO): The mad scientist who becomes aware of the dangerous secret of Mazinger Z.