This article commences with a discussion of the concept of public interest generally and more specifically within the context of the common law. It then considers the role of public interest tests in the Freedom of information (FOI) legislation of Commonwealth countries and presents a taxonomy of public interest tests in Commonwealth FOI legislation. It concludes by considering the merits of the ground-breaking developments in the approach to public interest tests in Australian FOI law and argues that there are valuable insights to be gained from the experience of this early FOI adopter.