<p>Human actions and interactions drive agri-food system outcomes. Sustainability transitions of such systems are shaped by changes in social relations encompassing new ways of doing, framing, knowing, organizing—largely understood as social innovations (SI). Previous SI conceptualizations in transition research draw substantially on energy studies. Hence, we address the recent appeal to expand SI research to other realms and specifically refer to the developed typology of SI in energy that we apply and adapt to the agri-food system. Guided by transition theory and SI research, this paper investigates the manifold activities of socially innovative agri-food initiatives engaged in challenging the dominant regime, the mechanisms through which these activities are realized and the barriers and drivers initiatives face. We conducted 22 semi-structured interviews with 17 initiatives engaged in making the local food system more sustainable from five territorial cases in Europe (Denmark, Germany, Italy, Poland) and Northern Africa (Morocco) in rural and urban areas. We derived a cluster structuring the socially innovative activities according to first, social (interaction) processes and second, agri-food fields. The initiatives assert these agri-food related social innovations (FSI) through four social (interaction) processes: cooperation, sharing, enabling, knowledge generation. We found that the socially innovative initiatives anchor their new ways through networks, practices and materials and institutions to six agri-food regime domains. Local political actors are perceived as conducive to their development. Governance for transition may take this into account as these political actors are better intertwined with the local area, capable of adapting policies to local needs.</p>