With the increasing level of complexity that leaders face today, represented in the accelerating pace of technology advancement and globalization, along with the climate change indicators reaching unprecedented levels, the need for good leadership quality has become more crucial than ever. The Framework for Strategic Sustainable Development provides a systems perspective, a principle-based definition and a way to strategically move towards sustainability, however still there is a need to specify what is required for leaders to lead organizations through this process.

The aim of the thesis is to explore how corporate leadership development companies can develop the essential leadership competencies to address the sustainability challenge. The study used the Key Competences in Sustainability Framework as a base to interview six leadership development companies from different areas in the world. The findings revealed that there is an essential need for self-development for leaders to handle complexity, as well as the need from leaders to create the proper conditions for their organizations to utilize the competences from the KCSF. Furthermore the results also showcased the need for standard common definition regarding sustainability.