Mary Jo Markey is an American film and television editor, who has also worked as an actress. Markey has edited several mainstream films including The Perks of Being a Wallflower and Mission: Impossible III. She has also worked as an editor on several television shows, such as three episodes of Felicity, Breaking News, Skin, fourteen episodes of Alias, and is also chief editor on Lost. She is a member of the American Cinema Editors and is a frequent collaborator with J. J. Abrams, having worked with him on three of his television shows (Felicity, Alias, and Lost) as well as editing his debut feature film (Mission: Impossible III), the 2009 Star Trek film and the 2011 film Super 8.
As of May 2013, Markey has been confirmed to be working with Abrams on the upcoming film Star Wars Episode VII, due to theaters in 2015.
Markey has been elected to membership in the American Cinema Editors.