Beginning in Fashion Design, O'Sullivan's entry to film was her work as Costume Designer for the Oscar-nominated independent drama 'Frozen River'. She has since designed the costumes for a diverse list of film and television projects including the iconic horror 'SINISTER' for Blumhouse Productions. 'MISSISSIPPI GRIND' & EQUALS' for A24 Films & 2021'S 'MAP OF TINY PERFECT THINGS' as well as 'GIFTED' for FilmNation Entertainment. O'Sullivan's designs are marked by an ability to mix realism and fantasy to form unique dystopian worlds still tethered to reality.
Upcoming Projects include 'DARK HARVEST' directed by David Slade (Hard Candy, 30 Days of Night, “Hannibal”)
Set in Halloween 1963 and based on the Norman Partridge’s novel of the same name.