The Golden Age of Comic Books was a period in the history of American comic books, generally thought as lasting from 1938 until the mid-1950s during which comic books enjoyed a surge of popularity, the archetype of the superhero was created and defined, and many of the most famous superheroes debuted.

Comic-book fans and historians widely agree that the Golden Age began no later than 1938 with the debut of Superman in Action Comics #1, published by DC Comics. Superman, the first comic book superhero, was so popular that superheroes soon dominated the pages of comic books. Between early 1939 and late 1941, Timely Comics, the 1940s predecessor of Marvel Comics, had million-selling titles that featured the Human Torch, the Sub-Mariner, and Captain America.

Although DC and Timely characters are more famous today, circulation figures suggest that in the 1940s the best selling superhero may have been Fawcett Comics' Captain Marvel. According to the article "Thunderstruck" by Ben Morse in Wizard #179 (September 2006):

By the mid 1940s, Fawcett Comics' Captain Marvel Adventures, starring the original "Shazam!"-shouting hero, sold roughly 1.4 million copies per issue, making it the most widely circulated comic book in America. Captain Marvel's sales soundly trounced Superman's self-titled series and Action Comics alike.

World War II had a significant impact. Comic books, particularly superhero comics, gained immense popularity during the war as cheap, portable, easily read tales of good triumphing over evil. Comic book companies showcased their heroes battling the Axis Powers; covers featuring a superhero punching Adolf Hitler or fighting buck-toothed Japanese soldiers have become icons of the age.

• 1950. For Timely Comics, the Golden Age ended with the cancellation of Captain America Comics at issue #75 (Feb. 1950) — by which time the series had already been Captain America's Weird Tales for two issues, with no superhero stories. The company's flagship title, Marvel Mystery Comics, starring the Human Torch, had already ended its run (with #92, June 1949), as had Sub-Mariner Comics (with #32, the same month).
• 1951. There was a long decline in the popularity of superheroes. At Timely Comics, Goodman began using the Atlas Comics logo on comics cover-dated Nov. 1951.
• 1954. The book Seduction of the Innocent by Dr. Fredric Wertham argued that superhero, crime, and horror comic books were a factor in corrupting young people and a cause of juvenile delinquency. The book contributed to a public outcry against the medium and the implementation of the industry's Comics Code.^[1]

Although Golden Age comic books may seem kitschy and simplistic by modern standards, the label is used because it was a time of the new artform's mainstream arrival; the creation of the "superhero" archetype; an explosion of new ideas and new characters, many still popular today; and the defining of the medium's artistic vocabulary and creative conventions by its first generation of writers, artists, and editors.