This guidebook aims to provide insights for working collaboratively with farmers in research. We identified and synthesized the literature on farmer-led research and farmer participatory research activities from around the world, with a focus on the North American context. Further, we shared our experiences and lessons learned from the first three years of Ecological Farmers Association of Ontario’s Farmer-led Research Program. This resource is meant to be used as a practical tool for researchers and practitioners looking to develop, implement, and evaluate farmer-led research programs.