This Review presents a comprehensive analysis of the amounts and distribution of public and philanthropic global cancer research funding between 2016 and 2023, including patterns of international collaboration and downstream research output, with an emphasis on the Commonwealth. We show that annual investment decreased globally each year, apart from a rise in 2021. Network analysis revealed that grant and publication collaborations between the Commonwealth, the USA, and the EU are facilitated by linkages through a core group of Commonwealth countries, including the UK, Australia, and Canada. There are inequities in research investment and low funding for treatment modalities for many cancers. These inequities also manifest in the central positioning of high-income Commonwealth countries in research collaborations, but also point to opportunities for high-income Commonwealth countries to facilitate linkages with low-income countries and support active cancer research in the USA and the EU. There is an urgent need to review research investment priorities, both within the Commonwealth and globally, to align with population needs and promote collaborative strategies that can build research skills and infrastructure in low-income settings to impact global cancer control. Finite resources should be invested wisely to achieve maximum improvements in mortality and alleviate the cancer burden.