Theoni V. Aldredge (August 22, 1928 – January 21, 2011) was a Greek-American stage and screen costume designer.
Born Theoni Athanasiou Vachlioti in Salonika in 1928, Aldredge received her training at the American School in Athens. She emigrated to the United States in 1949 and attended the Goodman Theatre at DePaul University, Chicago on a scholarship. Her first Broadway assignment was designing costumes for Geraldine Page in Tennessee Williams' Sweet Bird of Youth in 1959; her most recent was the 2006 revival of A Chorus Line. For 20 years she was the principal designer for Joseph Papp and also designed several musicals for Michael Bennett.
One of the most honored costume designers of the American theatre, Aldredge received three Tony Awards (for Annie, Barnum, and La Cage aux Folles), as well as 11 other Tony nominations, including such iconic productions as A Chorus Line, 42nd Street, and Dreamgirls. She received numerous honors from the Drama Desk awards and other theatrical groups. In 2002, she received the Irene Sharaff Lifetime Achievement Award from the Theatre Development Fund.
Aldredge worked extensively in film and television as well. Her productions included Network, Eyes of Laura Mars, and Rich and Famous. She received the Oscar and a British Academy Award for The Great Gatsby in 1974. Her designs for the film were adapted for a clothing line sold exclusively by Bloomingdale's in Manhattan.