BACKGROUND: The differences in cancer survival across countries and over time are well recognised, with progress varying even among high-income countries with comparable health systems. Previous research has examined several possible explanations, but the role of leadership in systems providing cancer care has attracted little attention. As part of the International Cancer Benchmarking Partnership (ICBP), this study looked at diverse aspects of leadership to identify drivers of change and opportunities for improvement across seven high-income countries. METHODS: Key informants in 13 jurisdictions were interviewed: Australia (2 states), Canada (3 provinces), Denmark, Ireland, New Zealand, Norway and United Kingdom (4 countries). Participants represented a range of stakeholders at different tiers of the system. They were recruited through a combination of purposive and 'snowball' strategies and participated in semi-structured telephone interviews. Interview transcripts were analysed thematically drawing on the World Health Organization (WHO) health systems framework and previous work analysing national cancer control programmes (NCCPs). RESULTS: Several facets of leadership were perceived as important for improving outcomes. These included political leadership to initiate and maintain progress, intellectual leadership to support those engaged in local implementation of national policies and drive change, and a coherent vision from leaders at different levels of the system. Clinical leadership was also viewed as vital for translating policy into action. CONCLUSION: Certain aspects of cancer care leadership emerged as underpinning and sustaining improvements, such as appointing a central agency, involving clinicians at every stage, ensuring strong leadership of cancer care with a consistent political mandate. Improving cancer outcomes is challenging and complex, but it is unlikely to be achieved without effective leadership, both political and clinical.