Pep Comics is an American comic book anthology series published by the Archie Comics predecessor MLJ Magazines Inc. (commonly known as MLJ Comics) during the 1930s and 1940s period known as the Golden Age of Comic Books. The title continued under the Archie Comics imprint for a total of 411 issues until March 1987.

Pep Comics introduced the superhero character The Shield, the first of the super-patriotic heroes with a costume based on a national flag (predating Captain America by over a year), as well as The Comet. The comic also introduced Archie Andrews, who eventually became the main focus of the company's extensive range of publications.

Pep Comics was the third anthology comic published by MLJ Magazines Inc., the precursor to what would become the publisher Archie Comics. The series was edited by Abner Sundell until issues #22–23, after which Harry Shorten took the reins until issue #65 (Jan. 1948). The first issue was launched in January 1940, following Blue Ribbon Comics (Nov. 1939) and Top-Notch Comics (Dec. 1939).

The format of Pep Comics was very similar to the previous titles; 64 pages of short strips, initially featuring a mixture of science-fiction stories such as "The Queen of Diamonds" (#1–12) by Lin Streeter (renamed "The Rocket and the Queen of Diamonds" in #2 (Feb. 1940)), about a John Carter of Mars-like hero trapped on another planet; the crime fighting story "The Press Guardian" (#1–11) by Jack Binder and Mort Meskin and later Abner Sundell and Meskin (retitled "Perry Chase, The Press Guardian" from #7); and three adventure tales, "Sergeant Boyle" by George Biro, about a soldier fighting with the British in Europe, as the United States was not yet involved in World War II, "The Midshipman", (#1–16) "Lee Sampson, Midshipman" from #6 (July 1940), following Lee Sampson through Navy College to his Graduation, and an adventure based on boxing, "Kayo Ward" (#1–28) by Phil Sturm. The last was similar to "The St Louis Kid" in Top-Notch Comics, both characters progressing through the boxing championships hierarchy throughout their series. Two short humor strips also featured in the first issue, "Jocko" and "Animal Antics", both by Dick Ryan, while "Buttonhead" by Quincy appeared in #2–5.

Pep Comics also starred superheroes and costumed characters, led by cover star and lead feature "The Shield – G-Man Extraordinary" by Harry Shorten and Irv Novick, a character who would remain in the title throughout the MLJ imprint and beyond. The Shield was mainly notable for being the first of the patriotic superheroes, who wore costumes based on the U.S. flag, 15 months before Captain America was introduced in Captain America #1 (March 1941). "The Comet" by Jack Cole ran for the first 17 issues alongside The Shield. The Shield and later The Hangman and Black Hood also featured in single page text stories during the MLJ years of the title; all comic books did this through the early 1960s to satisfy United States Postal Service requirements for magazine rates. The Shield also headed the Pep Comics readers club from #15 (May 1941), when the 'Shield G-Man Club' was introduced to the inside front cover of every issue, until The Shield finished in #65 (Jan. 1948). Although later to advertise other MLJ titles, during the war years each "bulletin" was largely filled with patriotic messages, details of local fan-clubs and new members information, all written as if a personal message from The Shield and his sidekick Dusty.

One unusual character who featured in early issues was "Fu Chang, International Detective", whose weird detective adventure stories were published in issues #1–11. Written by Joe Blair, with art by Jim Streeter, Fu Chang is a "Chinese scholar and detective, heir to the magic secrets of Aladdin who uses them only to bring peace and good-will to the people of his Chinatown." in stories liberally sprinkled with cod-Oriental talk, evil dragon criminals, and an aura of mysticism.

Another featured character was "Bentley of Scotland Yard", a mystery detective story originally by artist Sam Cooper and later Paul Reinman. Each story was in a horror/fantasy vein, with Bentley up against creatures such as a werewolf in #1, a monster in a lake in #2, and hunchbacks, devils and vampires through the first 41 issues of Pep Comics. These would always turn out to be hoaxes, usually perpetrated to cover up a murder, or for money or other gain. Each story ended with the same theme: a 'Bentley knows who ...' panel at the end of the penultimate page which listed the suspects and invited the reader to guess who committed the crime, followed by the revealing of the killer and the modus operandi on the final page.

With issue #11 (Jan. 1941), "Fu Chang, International Detective", "Perry Chase, The Press Guardian" and "The Rocket and the Queen of Diamonds" ended. To replace them, issue #12 (Feb. 1941) introduced two new characters. "Danny in Wonderland", a surreal fairy-tale adventure by Harry Shorten and Lin Streeter with stories loosely based on fairy tales such as "Cinderella", "Pinocchio", and The "Little Mermaid" (#12–39), while Ted Tyler, "The Fireball" (#12–20), 'sworn enemy of all who use fire for evil purposes' was a fireman who gained flame powers from a mixture of chemicals while fighting an arson attack. "Lucky Larson", a test pilot, filled the third place (#13–15). Further major changes came with the next two issues. "Lee Sampson, Midshipman" ended in #16 (June 1941); and Madam Satan was introduced in the same issue. Madam Satan, a dead villainess with a green face and the kiss of death, "the scourge of man, ready to go forth and leave a trail of misery and suffering in her wake" actually first appeared on the cover of the previous issue #15 (May 1941). She was written by Abner Sundell and initially drawn by Harry Lucey, although Joe Blair wrote her later adventures.