Mary Marvel is a fictional character and superheroine originally published by Fawcett Comics and now owned by DC Comics. Created by Otto Binder and Marc Swayze, she first appeared in Captain Marvel Adventures #18. The character is a member of the Marvel / Shazam Family of heroes associated with the superhero Shazam / Captain Marvel and is one of the first female spin-offs of a major male superhero, and predates the introduction of Supergirl by more than a decade.

Captain Marvel, also known as Shazam and the Captain, is a superhero in American comic books originally published by Fawcett Comics and currently published by DC Comics. Artist C. C. Beck and writer Bill Parker created the character in 1939. Captain Marvel first appeared in Whiz Comics #2, published by Fawcett Comics. He is the alter ego of Billy Batson, a boy who, by speaking the magic word "SHAZAM!", is transformed into a costumed adult with the powers of superhuman strength, speed, flight, and other abilities. The character battles an extensive rogues' gallery, most of them working in tandem as the Monster Society of Evil, including primary archenemies Black Adam, Doctor Sivana and Mister Mind. Billy often shares his powers with other children, primarily his sister Mary Batson and their best friend/foster brother Freddy Freeman, who also transform into superheroes and fight crime with Billy as members of the Marvel Family, also known as the Shazam Family.