Namor McKenzie, also known as Namor the Sub-Mariner, or simply Namor, is a character appearing in American comic books published by Marvel Comics. Created by writer-artist Bill Everett for comic book packager Funnies Inc., the character first appeared in Motion Picture Funnies Weekly #1 (uncirculated). Namor first appeared publicly in Marvel Comics #1. It was the first comic book from Timely Comics, the 1930s–1940s predecessor of Marvel Comics. During that period, known to historians and fans as the Golden Age of Comic Books, the Sub-Mariner was one of Timely's top three characters, along with Captain America and the original Human Torch. Moreover, Namor has also been described as the first comic book antihero.

An American comic book is a thin periodical originating in the United States, on average 32 pages, containing comics. While the form originated in 1933, American comic books first gained popularity after the 1938 publication of Action Comics, which included the debut of the superhero Superman. This was followed by a superhero boom that lasted until the end of World War II. After the war, while superheroes were marginalized, the comic book industry rapidly expanded and genres such as horror, crime, science fiction and romance became popular. The 1950s saw a gradual decline, due to a shift away from print media in the wake of television and the impact of the Comics Code Authority. The late 1950s and the 1960s saw a superhero revival and superheroes remained the dominant character archetype throughout the late 20th century into the 21st century.