Doctor-7 was an evil sorcerer and the arch-enemy of the supernatural sleuth Mark Merlin. By using his magical powers, he created a formula (with Radium) which enabled an evil ally named Morloo to remain on Earth, but the results were only temporary.
- This version of Doctor-7, including all history and corresponding appearances, was erased from existence following the collapse of the original Multiverse in the 1985–86 Crisis on Infinite Earths limited series. Even though versions of the character may have since appeared, this information does not apply to those versions.
- 5 Appearances of Doctor Seven (Earth-One)
- 10 Images featuring Doctor Seven (Earth-One)
- Quotations by or about Doctor Seven (Earth-One)
- Character Gallery: Doctor Seven (Earth-One)