People are an integral component of ecosystems. As such, the need to incorporate human dimensions into ocean and coastal research and management has been widely recognized. One well-known example is a consensus statement signed in 2005 by more than 220 U.S. academic scientists who argue for an ecosystem-based approach to marine management that “considers the entire ecosystem, including humans.” Nevertheless, far too many researchers and practitioners continue to overlook, or even misrepresent, the historical, political, and social components in marine social-ecological systems. Inadequate attention to these fundamental ecosystem components, often a result of disciplinary chasms between the natural and social sciences, is likely contributing to worldwide declines in the health of marine environments and the communities that depend on them. This symposium highlights cutting-edge interdisciplinary research on marine ecosystem–based management, marine spatial planning, and coupled social-ecological systems that puts humans back into marine systems in a variety of social, ecological, and geographical contexts. The studies draw on a wide range of methods, merging social and ecological perspectives to build a more holistic understanding of marine systems that is critical to the design and implementation of effective, equitable management policies and programs.