Umar (/ˈuːmər/) is a supervillain appearing in publications by the American publisher Marvel Comics. The character usually appears in stories featuring Doctor Strange, for whom she serves as an adversary. Created by writer Roy Thomas and artist Bill Everett, the character first appeared in Strange Tales #150 (November 1966).

A resident of the "Dark Dimension" of the Marvel Comics multiverse, Umar is a Faltine, a higher-dimensional energy being trapped in human form. She is the sister of Dormammu, a major adversary of Doctor Strange, and the mother of Clea, through which she has served as recurring enemy of Strange herself. Her powers have been depicted as exceeding those of Earth's sorcerers, including Strange, making defeating her very difficult. Umar and Dormammu have been historically depicted in a constant battle over the throne of the Dark Dimension, a mystical realm to which they had initially been banished by their people, over which Dormammu typically rules, whereas Umar is usually depicted in a form resembling a human woman.

One of Doctor Strange's "most iconic villains", the character has been described as "an unpredictable threat", and "a constantly plotting, wicked woman that would do anything, including betraying her own nigh-omnipotent brother for power". She is noted for her more cool-headed use of "guile and malevolent intelligence".

Umar first appeared in Marvel Comics' Strange Tales #150, in a Doctor Strange story written by Roy Thomas, and illustrated by Bill Everett under the editorial eye of Stan Lee. In the final panel of the previous month's Strange Tales #149 (written by Dennis O'Neil), however, her debut appearance was foreshadowed under a different name.

NEXT MONTH... The dramatic defeat of Kaluu -- and the introduction of the intriguing and totally unforgettable villainess of all time -- KARA Can you afford to miss it!

The cover of #150, however, ran the teaser "Exit Kaluu... enter Umar!" with her initial rendering. Appearing within on the final (tenth) page, Umar then spends most of issue #151 as a narrative tool, recapping the events which occurred during her banishment, for the benefit of the returning and new readers alike.

She has served as a major adversary Earth's Sorcerer Supreme, Doctor Strange. Her family ties would lead her to cross paths with Doctor Strange many times during the course of her publication history, during which she would work with her brother against Strange, and was not above exploiting Strange's romantic relationship with Clea to manipulate the sorcerer.

In 2005 Marvel published the miniseries Defenders: Indefensible, by Keith Giffen, J. M. DeMatteis, and Kevin Maguire, in which the Defenders reunited to confront Umar and Dormammu.