The Chief Sustainability Officer (CSO) role has evolved from a peripheral corporate function into a strategic leadership position at the heart of business transformation. As sustainability becomes increasingly tied to resilience, competitiveness, and long-term value creation, CSOs must navigate growing regulatory, political, and economic complexity. This discussion paper explores five strategic dilemmas shaping the future of the profession and invites sustainability leaders to reflect on how they can strengthen their influence and impact in a rapidly changing business landscape.