Alexandra M. E. Byrne (born 1962) is an English costume designer. Much of her career has focused on creating costumes for historical period dramas. These films include Persuasion (1995), Hamlet (1996), Elizabeth (1998), Captain Corelli's Mandolin (2001), Finding Neverland (2004), The Phantom of the Opera (2004), Elizabeth: The Golden Age (2007), and Mary Queen of Scots (2018). Byrne's costume design work has earned her five Oscar nominations, and she won the award for Elizabeth: The Golden Age. Since 2011, Byrne has also designed the costumes for many films in the Marvel Cinematic Universe, including Thor (2011), The Avengers (2012), Guardians of the Galaxy (2014), Avengers: Age of Ultron (2015), and Doctor Strange (2016).