Boosting board representation of women redresses structural unfairness and improves corporate governance and performance. The Change Our Game initiative, running over 3 years statewide in Victoria, Australia, mandated 40% representation of women on state sport boards. At the start, only 44% of state sport boards had 40% women representation; by the mandate deadline, this had increased to 93%. Using an institutional theory lens, the authors qualitatively analyzed four stakeholder groups: mandators, policy champions, operationalists, and mandate targets. Stakeholder sentiments were analyzed pre- and postmandate deadline over 3 years. Sentiments ranged from positive to equivocation to denigration. The mandate’s coercive pressure, supported by institutional legitimacy and work to accelerate changes, led to institutional change and achieved a significant increase in women board members. Change was grounded in strong ethical and cognitive support from mandate champions. Microsocial expressions of denigration and change resistance did not prevent successful change.