Although it began as a showcase for amateur athletes and international cooperation, the Olympics is now an enormous spectacle of both competitive sport and corporate sponsorship. Tokyo 2020 is the biggest Olympics ever in terms of number of sports, number of competitors, and number of sponsors. Drawing from the first-hand experiences of sports marketing expert Osamu Ebizuka, this chapter examines the development of Olympic corporate sponsorship and the key role of the Japanese advertising giant Dentsu in facilitating Japanese sponsors.