As a playwright, Upton created adaptations of "Hedda Gabler", "The Cherry Orchard", "Cyrano de Bergerac", "Don Juan" (with Marion Potts), "Uncle Vanya", "The Maids", "Children of the Sun" and "Platonov" for the Sydney Theatre Company (STC) and Maxim Gorky's "The Philistines" for London's Royal National Theatre.