Magneto is a fictional character appearing in the comic books published by Marvel Comics. Created by writer Stan Lee and artist Jack Kirby, the character is associated with the superhero group the X-Men as their primary antagonist since his (and their) first appearance in X-Men #1 (Sept. 1963).

Magneto is depicted as one of the most powerful mutants in the Marvel Universe, possessing the ability to generate and control magnetism. A Jewish Holocaust survivor, his actions are driven by the purpose of protecting the mutant race from suffering a similar fate. Characterizations of Magneto have varied through the years, from supervillain to anti-hero to even hero, but he is most often shown as an uncompromising militant and has engaged in acts of terrorism when he felt it was for the benefit of mutant-kind.

He has been featured in almost all X-Men animated series and video games and in the feature-film series, in which he is portrayed by Sir Ian McKellen.