This article reviews international literature on the demand for professional sport. The first part presents a conceptual framework for understanding the sources and determinants of the demand for professional sporting contests. The second part reviews empirical evidence on key determinants of attendance at sporting events, and on other sources of demand, such as broadcasting, sponsorship, and merchandising. The review concludes that there is still much to be learned about demand for professional sport, and that there are no simple lessons to be drawn from existing literature. But important messages do emerge from studies of demand for attendance with regard to effects of uncertainty of outcome, quality of contest, and quality of viewing.