In this paper we explore the role of leadership in enabling and accelerating the impact of strategic sustainability initiatives. We do this by first identifying the central integration challenges that strategic sustainability presents through an examination of the five levels of the Framework for Strategic Sustainable Development (FSSD). We describe the importance of relational leadership for strategic sustainability, or the ongoing process of meaning making and reflection within a nested system of the biosphere and society. We consider how this approach to leadership might address the relational tensions that continuously present themselves from this central challenge of integration. The primary contribution of this paper is that we have developed a conceptual model of relational leadership for strategic sustainability, grounded in practice, which describes specific practices and capabilities to support the FSSD in achieving its transformational potential. A secondary and related contribution is that we have examined two innovations advancing strategic sustainable organization management; the Strongly Sustainable Business Model Canvas and the Future-Fit Business Benchmark. We consider how these practices and capabilities embody relational leadership for sustainability, and how they help to support and measure success in the FSSD.