As long as the X-Men have been around, Magneto has been there to oppose them as he fought for mutant superiority in the early days of his career as a mutant terrorist, though he would eventually abandon his evil ways to become one of the leaders of the X-Men and the rest of his people living on the mutant island of Krakoa.
However, Magneto's first appearance outside of the comics wasn't even against the X-men, and he would make a number of appearances as a villain in Marvel's other animated series before featuring in the X-Men's many animated adaptations as well as starring in two successful live-action cinematic franchises that explored Magneto's tragic origins and devastating abilities.
12 Fantastic Four (1978)
While an altered non-mutant version of the character known as Dr. Magneto appeared on 1967's Spider-Man cartoon, the first actual appearance of Magneto was in 1978's Fantastic Four animated series episode "The Menace of Magneto."
This version of the character (voiced by John Stephenson) wore a unique version of his comic costume with altered colors and drove around in a metal copter-like vehicle that he controlled with his magnetic abilities, which were not revealed to be mutant in nature.
11 Iron Man: Armored Adventures (2009)
Iron Man: Armored Adventures was released in 2009 to capitalize on the success of the first live-action Iron Man movie, though it wasn't set in the same continuity and featured teenage versions of the characters that were CG-animated.
This version of Magneto (voiced by Ron Halder) was an amalgamation of the live-action version played by Ian McKellen and the Ultimate universe version of the character though he wore a wholly original uniform created for the series, and he first encountered Iron Man while dealing with an anti-mutant activist.
10 Spider-Man And His Amazing Friends (1981)
Spider-Man starred in two separate but loosely connected series in the eighties, with Spider-Man introducing a new version of Magneto (voiced by Walker Edmiston) with an altered costume who used the alias Mr. M when he held the world hostage.
Magneto would return (voiced by Michael Rye) with a more comics-accurate costume in Spider-Man and His Amazing Friends, which also starred Iceman and Firestar, whose flashback origins also included Magneto and his past with the X-Men.
9 The Super Hero Squad Show (2009)
The Super Hero Squad Show reimagined Marvel's heroes and villains in a kid-friendly Super Hero City, which featured Magneto (voiced by Maurice LaMarche) as a villain training his children Quicksilver and Scarlet Witch.
Magneto briefly worked with Doctor Doom before betraying him, and his troubled relationship with his children is briefly explored in the series, though not with any depth. An elderly version of the character with a magnetic walker appears in an alternate future episode as well to take out Sentinels and help the Squad.
8 Marvel Disk Wars: The Avengers (2014)
Marvel Disk Wars: The Avengers was a 2014 anime series that trapped Marvel's heroes into useable data disks so they could be summoned by a group of teen heroes as they fought against Loki and his assembled teams of classic and original villains.
Magneto (voiced by Banjō Ginga) only appeared in one episode, and while he was revealed as an old enemy of the X-Men, he helped the heroes stop a group of Sentinels while he attempted to recruit young mutant Surge into his Brotherhood. Magneto was mentioned in 2011's X-Men Anime but never appeared in the series.
7 Dark Phoenix (2019)
Michael Fassbender reprised his role as the young Magneto in 2019's X-Men: Dark Phoenix, which was the final film in Fox's cinematic franchise that attempted to readapt the iconic "Dark Phoenix Saga" from the comics.
Magneto appeared as the protector of a small community of mutants known as Genosha, however, Jean Grey's corruption into the Dark Phoenix and the death of Mystique brought him back into action, though he wore a very toned down outfit with a dark helmet when he returned to action, though the character was clearly tired of the fight.
6 Pryde of the X-Men (1989)
The X-Men's very first attempt at an animated series was the 1989 pilot episode Pryde of the X-Men, which introduced Kitty Pryde to the team as they dealt with Magneto and his Brotherhood of Mutant Terrorists.
Magneto (voiced by Earl Boen) featured a costume that was very similar to his usual comic appearance and he was even located on his Asteroid M headquarters, and he planned to divert a comet into the Earth in order to create a new ice age, making it easier for mutants to take over under his leadership.
5 Wolverine and the X-Men (2009)
While Genosha had appeared in other mediums before, 2009's Wolverine and the X-Men featured the mutant island of Genosha during a period of peace and prosperity under Magneto's rule, who had taken over the island and opened its borders to all mutants.
Magneto (voiced by Tom Kane) obviously had ulterior motives throughout the series and his peaceful paradise was revealed to be corrupted, with Magneto's motivations potentially leading to a dark future that Professor Xavier had warned the X-Men about from the future.
4 X-Men: Evolution (2000)
While Magneto (voiced by Christopher Judge) is mostly a dark figure manipulating characters and events from behind-the-scenes in the first season of 2000's X-Men: Evolution, he continued to act as one of the main opposing forces to Professor X and his teen team.
Magneto's children Quicksilver and Scarlet Witch featured heavily on the series as members of Mystique's Brotherhood, and their familial connection was explored in depth. This version of Magneto had also technologically evolved his mutant abilities, making him one of the most powerful mutants on the series.
3 X-Men (1992)
One of the most recognized versions of the character outside of the comics and cinematic franchise is 1992's portrayal of Magneto (voiced by David Hemblen) in the fan-favorite X-Men: The Animated Series.
Magneto debuted early in the series as ane enemy of the X-Men, though he would find himself allied with Xavier's mutants more often than not as they dealt with huge threats to mutantkind together over the course of five seasons that adapted numerous storylines and explored the past and future of Marvel's mutants.
2 Prequel Trilogy (2011-2016)
When Fox rebooted its successful live-action X-Men film franchise, it explored the history of Professor Charles Xavier and Magneto and the events that led to their respective paths, with Michael Fassbender portraying the younger version of Ian McKellen's character.
Magneto briefly joined the team in 2011's X-Men: First Class before launching his war against humanity in 2014's X-Men: Days of Future Past (which also featured McKellen in future scenes), and fell under the sway of an eternal mutant in 2016's X-Men: Apocalypse, each of which introduced new versions of his cinematic costume.
1 Original Trilogy (2000-2006)
Sir Ian McKellen brought the character to life in 2000's X-Men, which would lead to an ongoing franchise that featured five appearances for McKellen's Magneto, with his first costume standing out due to its simplicity, though his helmet would continue to evolve with each film.
McKellen grew the character over the various films that included 2003's X2: X-Men United, 2006's X-Men: The Last Stand, a brief cameo in the mid-credit scene of 2013's The Wolverine, and a final appearance in 2014's X-Men: Days of Future Past.