This paper presents the results of action research conducted from 2009 to 2015 on the dynamics of resource conflict concerning fisheries and livelihoods in the Tonle Sap Lake, as well as the institutional context and strategies for institutional adaptation to address such conflicts equitably. Over the past 15 years, Cambodia has made significant advances in building the policy framework, regulations and institutions to support community‐based fisheries management and increase the sector's contribution to the rural economy. However, fundamental challenges of increased resource conflict and loss of livelihoods by the most vulnerable remain. Key sources of conflict include destructive and illegal fishing practices, clearing of flooded forests, competing uses of land and water, and overlapping resource claims. Addressing these challenges requires collective action by all key actors: local fishers, the private sector, civil society, development partners, and government from the local to the national level. We identify and elaborate upon four governance priorities: (1) clarify roles and responsibilities in fisheries management; (2) link civil society and government efforts in law enforcement; (3) strengthen partnerships for livelihoods development; and (4) integrate fisheries management into decentralised development planning.