Peer research is about academics and other professional researchers working with and training non-researchers to do research on issues that they have lived experience of and that involves collecting data from people like them—their peers. In health promotion specifically, peer research is a form of community-based participatory research and is based on a recognition that community members are experts on their own lives and so are best placed to identify and plan to solve their own health problems. Peer researchers are able to leverage their insider status within a community to improve research findings and knowledge production compared to nonparticipatory approaches. The act of involving community members as peer researchers can also support social justice and health promotion outcomes. However, there are practical, ethical, role, epistemological, and emancipatory challenges with peer research. In this chapter, strategies to support implementation of peer research in health promotion research are discussed, including involving peers as early as possible, clarifying roles and responsibilities, paying peer researchers for their contributions, and providing training and ongoing support to peer researchers. However, the relative newness of peer research as a research methodology means that a lot of questions remain about its operation and effectiveness; the majority of evidence about the method comes from informal evaluation, academic researcher observations, and feedback from peer researchers. More systematic investigation is needed to understand the utility of peer research in different health promotion contexts.