CONTEXT: Sustainability-Oriented Innovation (SOI) is recognized as a way to address agrifood system sustainability challenges. Because of its complexity, SOI requires inter-organizational collaboration between actors within and around value chains. Since farming practices account for a large part of the environmental impact of food products, farmer involvement in SOI processes is key. However, there is a lack of evidence on the degree of farmer engagement in inter-organizational collaboration, as well as the diversity of partners involved. Moreover, our understanding of the heterogeneity of collaboration in relation to the sustainability dimensions of the innovation SOI processes is limited.OBJECTIVE: The objectives of our research are twofold. First, to propose a novel conceptualization of SOI, converging the sustainability specificities of the innovation process and the characteristics of the collaboration supporting the innovation process. Second, to unpack heterogeneous forms of collaboration in SOI with attention to farmer engagement in these forms.METHODS: We developed the SOI framework and analyzed SOI processes in the fruit and vegetable sector across Europe. A multiple correspondence statistical analysis was carried out based on data from more than one hundred value chains that have implemented a SOI process. A hierarchical clustering analysis was performed to reveal patterns of collaboration in SOI.RESULTS AND CONCLUSIONS: The results show different patterns of collaborative SOI in European fruit and vegetable chains. The SOI differ as regards to three specific dimensions: the diversity, the direction, and the distribution; and they rely on various collaboration forms. Seven clusters are analyzed and discussed, with specific attention to the farmer engagement in the collaboration forms. We differentiated between 1) Intermediary-led farm & food innovation with farmer collaboration; 2) Intermediary-led short food supply chain innovation with farmer collaboration; 3) Processor-led green food product innovation without farmer collabo-ration; 4) Farmer-led sustainable agricultural practices innovation with a collaborative network; 5) Farmer-led coupled innovation with downstream integration; 6) value chain actor-led coupled innovation with farmer collaboration; 7) Retailer-led distribution innovation without farmer collaboration. The relationship between diverse collaboration forms and SOI dimensions is discussed.SIGNIFICANCE: Revealing the heterogeneity of collaboration forms in SOI processes is important for developing sound policies. Given the significant role of farmers in sustainable agrifood system transitions, this paper reveals various levels of farmer engagement in collaborative SOI processes in value chains. Results have implications for mission-oriented policies since they allow a more precise and targeted approach to agrifood chains within the broader agrifood system transformation.