Healthy ocean ecosystems are needed to sustain people and livelihoods and to achieve the United Nations Sustainable Development Goals. Using the ocean sustainably requires overcoming many formidable challenges: overfishing, climate change, ocean acidification, and pollution. Despite gloomy forecasts, there is reason for hope. New tools, practices, and partnerships are beginning to transform local fisheries, biodiversity conservation, and marine spatial planning. The challenge is to bring them to a global scale. We dissect recent successes using a complex adaptive-systems (CAS) framework, which acknowledges the interconnectedness of social and ecological systems. Understanding how policies and practices change the feedbacks in CASs by altering the behavior of different system components is critical for building robust, sustainable states with favorable emergent properties. Our review reveals that altering incentives—either economic or social norms, or both—can achieve positive outcomes. For example, introduction of well-designed rights-based or secure-access fisheries and ecosystem service accounting shifts economic incentives to align conservation and economic benefits. Modifying social norms can create conditions that incentivize a company, country, or individual to fish sustainably, curb illegal fishing, or create large marine reserves as steps to enhance reputation or self-image. In each example, the feedbacks between individual actors and emergent system properties were altered, triggering a transition from a vicious to a virtuous cycle. We suggest that evaluating conservation tools by their ability to align incentives of actors with broader goals of sustainability is an underused approach that can provide a pathway toward scaling sustainability successes. In short, getting incentives right matters.