History of character is unknown.
- Temporal Mechanics: Jeff Smith is an expert in the field of temporal mechanics, quantum theory and the relationship between energy and matter as it pertains to the Space/Time continuum.
- This version of Jeffrey Smith (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.
- 41 Appearances of Jeffrey Smith (Earth-One)
- 5 Images featuring Jeffrey Smith (Earth-One)
- Quotations by or about Jeffrey Smith (Earth-One)
- Character Gallery: Jeffrey Smith (Earth-One)