As climate change, resource overexploitation, and pollution leave ever more lead to ever more devastating outcomes, ocean ecosystems, economies, and people are all affected. With coasts on the Atlantic, Pacific, and Arctic, Canada faces a formidable challenge in building resilient, sustainable oceans and supporting the communities that rely on them. Sea Change reports on the OceanCanada Partnership, a multidisciplinary project to take stock of what we know about Canada's oceans, construct possible scenarios for coastal regions, and create a national dialogue and vision. Three themes emerge from this impressive synthesis of social, cultural, economic, and environmental research: ocean change, access to ocean resources, and ocean governance. Indigenous and non-Indigenous scholars and practitioners focus on finding solutions to rapid environmental and social transformation, outlining the implications for legislation, and offering policy recommendations. Increasingly, civil society will have to advocate for oceans, and Sea Change will empower the voices of those who take up that task.