This paper examines gender diversity in sport governance globally. Theoretically, the study draws on gender dynamics in organisations, in particular on Kanter’s concepts of gender ratios and critical mass. An audit of the gender ratio on boards of National Sport Organisations was conducted in 45 countries. Data were collected through the Sydney Scoreboard, an interactive website that tracks women’s presence on sport boards internationally. Findings show that women remain under-represented on three key indicators: as board directors, board chairs and chief (...) executives. Few countries have achieved a critical mass of 30 % representation and no continent has achieved the critical mass on any of the three indicators. Women’s under-representation in sport governance is due to complex gender dynamics. Gender diversity on sport boards is associated with four interwoven dimensions of gender relations: production, power, emotion and symbolism. The combination of the four dimensions produces an environment that may or may not be conducive to gender diversity. (shrink)