The Intersectoral Action Fund (ISAF) is the first Public Health Agency of Canada (PHAC) program explicitly dedicated to support collective action across sectors on the social determinants of health to reduce health inequities. This grant program seeks to strengthen capacity and build knowledge and tools to enable partners to work together across sectors to advance action on the social determinants of health. The program prioritizes funding upstream projects, or projects that are addressing the root causes of ill health and health inequities.