In this article, we bring together the existing sociological knowledge on fashion, and the main part of the review is of classical and recent sociological work. To further the development of this largely interdisciplinary field, we also highlight the key points of research in other disciplines. We define fashion as an unplanned process of recurrent change against a backdrop of order in the public realm. We clarify this definition after tracing the origins and history of fashion. As a social phenomenon, fashion has been culturally and economically significant since the dawn of Modernity, and has increased in importance with the emergence of mass markets, both in terms of production and consumption. Most research on fashion is concerned with dress, but we argue that there are no domain restrictions that should constrain fashion theories. We identify venues around which sociologists could develop further research on the topic of fashion.