Captain Atom is the name of several superheroes appearing in American comic books, initially owned by Charlton Comics before being acquired in the 1980s by DC Comics.^[​1] All possess some form of energy-manipulating abilities.

Captain Atom was created by writer Joe Gill and artist/co-writer Steve Ditko, and first appeared in Space Adventures #33 (March 1960).^[​2] Captain Atom was initially created for Charlton Comics, but was later acquired by DC Comics and revised for DC's Post-Crisis continuity.^[​3] In 2011, DC Comics relaunched its superhero comics and rewrote the histories of some characters from scratch, including Captain Atom, giving him a new origin, appearance and slightly altered powers. Captain Atom was the character inspiration for Doctor Manhattan, who was featured in the miniseries (and later live-action film adaptation) Watchmen, which would be connected to the DC Universe in the miniseries Doomsday Clock.