Captain Marvel, Jr. is a fictional character, derived from the DC Comics (formerly Fawcett Comics) character Captain Marvel.

Captain Marvel, Jr. was an orphaned newsboy named Freddy Freeman who was fatally wounded in a battle between Captain Marvel and his enemy Captain Nazi . Marvel transformed into his civilian identity, Billy Batson, and brought the dying Freeman to the wizard Shazam, who had given Batson the powers of Captain Marvel. Shazam granted this wish: when Batson transformed into Marvel again by shouting the magic word "Shazam!", Freeman shouted "Captain Marvel!" and was also transformed. Freeman, who was now called Captain Marvel Jr., resembled a younger Captain Marvel, though with a yellow-on-blue costume with a red cape, rather than Marvel's yellow-on-red with a white cape. Whenever Freeman says the magic words "Captain Marvel!" he transforms into Captain Marvel Jr. or returns from that form to that of Freddy Freeman. However, as a result of Captain Nazi's near-fatal attack, Freddy is permanently lame in his left leg (although Captain Marvel, Jr. bears no such impediment).

Captain Marvel Jr. also stood out as a character who was unable to say his own name, since he'd transform back into Freddy Freeman if he did.

After Fawcett Comics folded in the early 1950s, Capt. Marvel Jr. remained unpublished, alongside the rest of the Marvel Family, for years. In the early 1970s, DC Comics purchased the rights to the Marvel Family characters and revived them in a new series entitled Shazam!. In recent years, as a part of the unified, post-Crisis DC Universe, Capt. Marvel Jr. became a member of the Teen Titans for a time, calling himself CM3 ("Captain Marvel III") to allow him to identify himself without changing.

It has been said that Elvis Presley was a fan of Captain Marvel, Jr., and styled his trademark haircut after that of the comic book character.