A former Police officer, after leaving the force Jonny Double opened up a private detective agency in San Fransisco. During the course of a remarkable career, he became a frequent ally of Wonder Woman, initially during the time that she had lost her powers, and also assisted the Challengers of the Unknown on at least one case, as well as being hired by Nasthalthia Luthor, an enemy of Supergirl as part of a scheme to expose her secret identity (Double ended up teaming up with Supergirl against Doctor Tzin-Tzin before telling his original client he would not take his case). He also opposed the forces of Kobra on occasion. During the Crisis on Infinite Earths, Double attended a detectives convention and was present when the villain Angle Man was murdered there.
- This version of Jonathan Double (Earth-One), including all history and corresponding appearances, was initially erased from existence following the collapse of the original Multiverse in the 1985–86 Crisis on Infinite Earths limited series. However the ending of Convergence retroactively prevented that collapse, saving all the alternate realities, though in an "evolved" form. Even though versions of the character may have since appeared, this information does not apply to those versions.
- 13 Appearances of Jonathan Double (Earth-One)
- 2 Images featuring Jonathan Double (Earth-One)
- Quotations by or about Jonathan Double (Earth-One)
- Character Gallery: Jonathan Double (Earth-One)