The Scarlet Witch (Scarlet Witch, Wanda Maximoff) is a fictional superhero who appears in comics published by Marvel Comics. It appeared for the first time in X-Men # 4 (1964) and was created by Stan Lee and Jack Kirby, debuting in the so-called Silver Age of Comics. In her early days, she was introduced as a supervillain along with her twin brother Quicksilver, both founding members of the Brotherhood of Mutants. The character, originally presented as a mutant, possesses abilities to alter reality in unspecified ways and is also a powerful sorceress. Later, he would become a regular member of The Avengers. In time, he would marry his teammate Vision.

Described as the children of the Buzzer (superhero from the Golden Age of Comics), the Scarlet Witch and her brother Quicksilver later established themselves as descendants of the supervillain Magneto (who was unaware of their existence). Born to Magneto's estranged wife in Transia, they were both left in the care of their Roma adoptive parents, and she was raised as Wanda Maximoff. In a retcon, much later, it was revealed that she and Quicksilver were not mutants, but were abducted and used as genetic experiments by the High Evolutionary and later tricked into believing that Magneto was her father.

The Scarlet Witch has appeared for five uninterrupted decades in the pages of Marvel comics, starring in two limited series of the same name along with her husband Vision, and being a regular member in the installments of The Avengers. The character has appeared in other Marvel merchandise, including animated movies, arcade and video games, television series, action figures, and trading cards. The Scarlet Witch is portrayed by actress Elizabeth Olsen 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) and Avengers: Endgame (2019). Olsen also plays the role in the Disney + series WandaVision (2021) and the film Doctor Strange in the Multiverse of Madness (2022).