William Maxwell "Bill" Gaines was an American publisher and co-editor of EC Comics. Following a shift in EC's direction in 1950, Gaines presided over what became an artistically influential and historically important line of mature-audience comics. He published the satirical magazine Mad for over 40 years.

Entertaining Comics, more commonly known as EC Comics, was an American publisher of comic books, which specialized in horror fiction, crime fiction, satire, military fiction, dark fantasy, and science fiction from the 1940s through the mid-1950s, notably the Tales from the Crypt series. Initially, EC was owned by Maxwell Gaines and specialized in educational and child-oriented stories. After Max Gaines' death in a boating accident in 1947, his son William Gaines took over the company and began to print more mature stories, delving into the genres of horror, war, fantasy, science-fiction, adventure, and others. Noted for their high quality and shock endings, these stories were also unique in their socially conscious, progressive themes that anticipated the Civil Rights Movement and the dawn of the 1960s counterculture. In 1954–55, censorship pressures prompted it to concentrate on the humor magazine Mad, leading to the company's greatest and most enduring success. Consequently, by 1956, the company ceased publishing all of its comic lines except Mad.