Thailand’s climate change governance is assessed on the basis of the polycentric and the Climate Action Tracker (CAT) framework. This framework is a systematic approach to understand current climate change governance and considers the aspects of key enabling factors for effective climate actions towards a zero emissions society. The results show that, over the last two decades Thailand has continually developed important elements of governance architecture to better manage climate change challenges. The orientation of Thailand’s climate change governance has been steadily reformulated to move towards a polycentric mode, with diverse instruments formulated, cross-scale institutional arrangement and linkages established, multi-level actors, and different kinds of knowledge produced. One of Thailand’s polycentric governance developments is proactive engagement of public and private actors to enable more effective management of climate change. An additional CAT-based analysis consistently highlights that Thailand has advanced political commitments towards a zero-emissions society. Much progress can also be seen for the elements related to policy processes and stakeholder engagement, but the institutional framework regulating Thailand’s governmental and ministerial processes for effective climate action is still weak. To advance towards more polycentric governance, Thailand should make efforts to focus on further strengthening existing mechanisms for climate change responses in the Paris Agreement (PA) regime, especially encouraging institutional reform and enhancing central-to-local coordination and decision-making processes. Moreover, stronger engagement of local-level actors provides a great opportunity to enhance polycentric governance and improve climate change responses at the front line.