This PhD projects contributes to understanding coastal marine governance in Fiji and Solomon Islands. It examines community-based marine resource management (CBMRM) approaches, which are based on customary marine governance systems, while also considering interactions with the national legal governance frameworks for coastal fisheries in both countries. Based on qualitative research methods and analysis, this study uses a range of conceptual and analytical lenses. A social-ecological system (SES) perspective serves to identify key contextual factors and actors that influence the governance of coral-reef SESs. A gender lens is used to distill women's and men's differentiated roles and participation in marine resource use and governance. Furthermore, this study ascertains drivers of local (non-) compliance with and enforcement of CBMRM. Finally, a legal pluralism perspective is taken to scrutinize the interactions across the different governance systems in place, i.e., customary governance systems and the national legal governance systems for coastal fisheries. Overall, this thesis aims to address the challenge of how to sustainably use and manage marine (coral reef) resources in Fiji and Solomon Islands. It identifies points of leverage to improve coastal marine governance that are relevant both for policy and practice, and which may be useful for the local, national and subnational levels.