This working paper, Green Public Procurement (GPP) in ASEAN: Technical Guidance and Practical Tools for Implementation, was developed as an initiative of the SWITCH-Asia Policy Support Component (PSC) to support the acceleration of Green Public Procurement (GPP) implementation in ASEAN Member States (AMSs). The paper examines how GPP is recognised under different frameworks as a strategic tool to stimulate markets for sustainable goods and services, reduce environmental impacts, and enhance social equity. Leveraging SWITCH-Asia’s extensive experience in GPP across ASEAN, this paper provides actionable strategies to accelerate GPP adoption, address implementation gaps, and position GPP as a key driver of sustainable development, regional market integration, and economic resilience.