The League of Extraordinary Gentlemen (LoEG) is a comic book series (inspired by the 1960 British film The League of Gentlemen) co-created by writer Alan Moore and artist Kevin O'Neill which began in 1999. The series spans four volumes, an original graphic novel, and a spin-off trilogy of graphic novella. Volume I and Volume II (released as two six-issue limited series) and the graphic novel Black Dossier were published by the America's Best Comics imprint of DC Comics. After leaving the America's Best imprint, the series moved to Top Shelf and Knockabout Comics, which published Volume III: Century (released as three graphic novella), the Nemo Trilogy (a spin-off of three graphic novella centered on the character of Nemo), and Volume IV: The Tempest (originally released as a six-issue limited series). According to Moore, the concept behind the series was initially a "Justice League of Victorian England" but he quickly developed it as an opportunity to merge elements from many works of fiction into one world.

Elements of Volume I were used in a loosely adapted feature film of the same name, released in 2003 and starring Sean Connery in his last live-action role.