Prison health research focuses on the health of people who experience imprisonment. Prison health research represents a means to improve the health status of this population and to achieve health equity. To advance this field, we need to strengthen instrumental factors such as the research workforce, funding, and legislation, policy, and ethics guidance. Through partnering in the research process with people with lived experience of imprisonment and other knowledge users, we can improve research relevance and acceptability. All prison health research should explicitly focus on moving research findings into action, for example, to inform health care and health promotion in prisons. Finally, we need to address important gaps in knowledge and use high-quality methods to optimize research validity and impact.