Supplier development for sustainability is a critical element of sustainable supply chain
management and requires extensive multi-stakeholder collaboration. This article establishes a
conceptual four-stage framework to analyse the collaborative mechanisms of supplier development practices, and presents an exploratory, qualitative analysis to identify the major
contributors of sustainable supplier development practices, such as NGOs, industrial associations, consulting firms, etc. Based on semi-structured interviews towards 63 organisations from different regions and industries, this article identifies three types of contributors: Drivers, Facilitators and Inspectors. Instead of traditional stakeholder engagement processes, these contributors actively collaborate with buying firms and suppliers to design, implement and evaluate sustainable supplier development programs. The article then provides a matrix to describe the supply chain coverage and supplier performance of supplier development practices, given the absence or positive involvement of Facilitators and Inspectors. We conclude our study by suggesting future research directions as well as discussing managerial implications.