Background: There is well-established variation in cancer survival across high-income countries with seemingly-similar health systems. There is much research on reasons for these differences, but the role of leadership has been under-researched despite being one of the WHO 'building blocks' that underpin a functioning health system. Leadership is variously defined as including governance, stewardship, responsibility and accountability. As part of the International Cancer Benchmarking Partnership, this study looked at these diverse aspects of leadership to identify drivers of change and improvement across a range of high-income countries. Methods: Cancer strategy documents were analysed from 22 jurisdictions: Australia (3 states), Canada (10 provinces), Denmark, Ireland, New Zealand, Norway, and UK (4 countries). Key informants in 15 of these jurisdictions, representing a range of stakeholders, were recruited through a combination of purposive and 'snowball' strategies, and invited to participate in semi-structured interviews. Documents and interview transcripts were analysed using a thematic approach. Results: Different facets of leadership emerged: diffused vs centralised (including the central role of a cancer agency in some places); national, regional and local leadership structures; links between primary and secondary care. This study, however, demonstrated a central role for sustained leadership and political commitment, crucial for initiating and maintaining progress, as was a coherent vision that supported the implementation of national policies locally. Clinical leadership emerged as vital for translating policy into action. Conclusions: Improving cancer outcomes is challenging and complex but is unlikely to be achieved without effective leadership and sustained political commitment that can create effective co-ordination of care.