Multi-actors innovation platforms (MAIPs) are increasingly deployed as a model for participatory and inclusive innovation to address the challenges of sustainability in complex systems like the agri-food systems. The facilitation of co-innovation and multi-actor partnerships is critical to the success of MAIPs, as a common lesson learned across the multitude of initiatives around the world. The guideline was developed for Master Trainers to train MAIP facilitators. The guideline first gives an introduction to the definiton, principles, design, establishment and facilitation of MAIPs. Then, it explains the principles, curriculum development and preparation, and implementation, monitoring and evaluation of MAIP training of facilitators courses as well as mentoring of MAIP facilitators. Finally, the guideline offers a generic structure of MAIP training of facilitator curriculum. It is suggested that this guideline be used as a reference for MAIP master trainers to formulate context-specific training objectives, approach, learning activities and field-based action.