The Scarlet Witch (Wanda Maximoff) is a fictional character appearing in American comic books published by Marvel Comics. The character was created by writer Stan Lee and artist Jack Kirby. Her first appearance was in The X-Men #4 (March 1964) in the Silver Age of Comic Books. Originally said to have the ability to alter probability, the Scarlet Witch has been depicted as a powerful sorceress since the 1980s and was later said to be powerful enough to alter reality. For most of her comic book history, she is portrayed as a mutant, a member of a fictional subspecies of humans born with an "X-gene" that grants superhuman abilities and traits. This was revised via a 2015 storyline establishing that her superhuman traits are a result of experimentation done by High Evolutionary when she was a child.
Scarlet Witch is first depicted as a reluctant supervillain along with her twin brother Pietro Maximoff / Quicksilver, both founding members of the Brotherhood of Mutants. A year after her debut, she joined the Avengers superhero team and ever since has often been depicted as a regular member of that or related teams (such as the West Coast Avengers and Force Works). In 1975, she married her android teammate Vision, later using borrowed magical forces to make herself pregnant, resulting in twin sons William ("Billy") and Thomas. Stories in 1989 wiped Thomas and Billy from existence (they would later reappear as the heroes called Wiccan and Speed) and removed Vision's emotions, leading to the annulment of his and Wanda's marriage.
The character's in-universe backstory and parentage have changed more than once. During the 1960s, she and Quicksilver are said to be the mutant twin offspring of two human Romani parents, Django and Marya Maximoff. Later, it is said the children were adopted, given to the Maximoffs by the geneticist called the High Evolutionary, leaving their true parentage a mystery. In 1974, it is said their parents are Golden Age heroes Bob Frank / Whizzer and Madeline Joyce Frank / Miss America. Wanda then refers to herself as Wanda Frank for a time. In 1982, Magneto concludes he is Wanda and Pietro's father. In 2014, the AXIS crossover revealed Pietro and Wanda are not related to Magneto. In 2015, the twins discover they are not mutants and their superhuman traits are the result of the High Evolutionary's experiments. The 2015–2017 Scarlet Witch series reveals Wanda and Pietro's adopted parents Django and Marya Maximoff are biologically their aunt and uncle. Their real mother is confirmed to be Natalya Maximoff, the previous Scarlet Witch, a sorceress whose father was the Scarlet Warlock.
Along with starring in two self-titled limited series of her own, the character appears in several Marvel-related films, television series, video games, and merchandise. Additionally, Elizabeth Olsen portrays Wanda Maximoff / Scarlet Witch in the Marvel Cinematic Universe films Captain America: The Winter Soldier (2014), Avengers: Age of Ultron (2015), Captain America: Civil War (2016), Avengers: Infinity War (2018), Avengers: Endgame (2019), as well as the Disney+ miniseries WandaVision (2021). Olsen will reprise the role in the upcoming film Doctor Strange in the Multiverse of Madness (2022).