John Lindley Byrne is a British-born American writer and artist of superhero comics. Since the mid-1970s, Byrne has worked on many major superheroes; with noted work on Marvel Comics's X-Men and Fantastic Four. Byrne also facilitated the 1986 relaunch of DC Comics's Superman franchise with the limited series The Man of Steel, the first issue of which featured the comics' first variant cover.

Superhero comics is one of the most common genres of American comic books. The genre rose to prominence in the 1930s and became extremely popular in the 1940s and has remained the dominant form of comic book in North America since the 1960s. Superhero comics feature stories about superheroes and the universes these characters inhabit.