The Comics Code Authority (CCA) was a self-regulatory organization formed in 1954 by the Comics Magazine Association of America that, at the height of its influence, served as a de facto censor for most of the U.S. comic book industry. The code was voluntary, as there was no law requiring its use, and it was designed to reassure advertisers, retailers, and parents about the content of comic books. The CMAA formed the Comics Code Authority at the height of a moral panic around comics that coincided with the United States Senate Subcommittee on Juvenile Delinquency hearings of 1954 and the publication of psychiatrist Fredric Wertham's book Seduction of the Innocent, both of which increasingly called for government regulation of comic books. Member organizations submitted comics to the CCA, which screened them for adherence to its code, then authorized the use of their seal on the cover if the book was found to be in compliance. Some publishers, mostly of children's comics (including Dell, Western, and Gilberton) never used the Code, but outside of children's comics, the lack of a CCA seal meant that distributors were unlikely to distribute a particular comic book. The power of the Code began to wane across the 1960s and 1970s, owing in part to changes in the distribution of comic books, the rise of underground comix, and the emergence of graphic novels and other adult comics. By 2010, only three major publishers still adhered to it: DC Comics, Archie Comics, and the now defunct Bongo Comics. Bongo broke with the CCA in 2010. DC and Archie followed in January 2011, rendering the code defunct.

The establishment of the Code followed years of significant backlash to the content of certain comic books as well as children's consumption of comics. The first widely-reprinted critique of comic books came from children's author Sterling North in 1940 when he declared that comics were "graphic insanity" in a column for the Chicago Daily News, which was later reprinted in the academic journal Childhood Education. After abating somewhat due to World War II, the anti-comics movement sprang back to life in 1948 due in part to the wider publication of Fredric Wertham's anti-comics critiques in magazines like Collier's and Saturday Review of Literature.

The Comics Magazine Association of America (CMAA) was formed in September 1954 in response to a widespread public concern over graphic violence and horror imagery in comic books. It named New York magistrate Charles F. Murphy (1920–1992), a specialist in juvenile delinquency, to head the organization and devise a self-policing "code of ethics and standards" for the industry. He established the Comics Code Authority (CCA), basing its code upon the largely unenforced code drafted by the Association of Comics Magazine Publishers in 1948, which in turn had been modeled loosely after the 1940 Hollywood Production Code, also known as the "Hays Code".

Before the CCA was adopted, some cities had already organized public burnings and bans on comic books. The city councils of Oklahoma City, Oklahoma, and Houston, Texas, passed ordinances banning crime and horror comics, although an attempt by Los Angeles County, California, was deemed unconstitutional by the courts. In his introduction to Archie Americana Series Best of the Fifties, editor Victor Gorelick reminisced about the code, writing, "My first assignment, as a new art assistant, was to remove cleavages and lift up low cut blouses on Katy Keene." He also wrote of Archie artist Harry Lucey that, "His sometimes suggestive storytelling–and he was one of the best–almost cost him his job. When his pencilled stories came in, the characters were dressed on one page only. The inker, a woman, Terry Szenics, later had to draw clothes on the characters on the remaining pages."

Although the CCA had no official control over the comics publishers, most distributors refused to carry comics that did not carry the seal. However, two major publishers of comics–Dell Comics and Gold Key Comics–did not display the seal, because their output was subject to a higher authority: their licensors, which included Walt Disney and the producers of many TV shows aimed at children.

Some publishers thrived under these restrictions, while others adapted by cancelling titles and focusing on code-approved content; still others went out of business. In practice, the negative effect of not having CCA approval was lack of distribution by the comic book wholesalers, who, as one historian observed, "served as the enforcement arm of the Comics Code Authority by agreeing to handle only those comics with the seal."

Publisher William Gaines believed that clauses forbidding the words "crime", "horror", and "terror" in comic book titles had been deliberately aimed at his own best-selling titles Crime SuspenStories, The Vault of Horror, and Tales from the Crypt.

Wertham dismissed the code as an inadequate half-measure. Comics analyst Scott McCloud, on the other hand, later commented that it was as if, in drawing up the code, "the list of requirements a film needs to receive a G rating was doubled, and there were no other acceptable ratings!"