Abstract: The adoption of the UN 2030 Agenda and the Sustainable Development Goals (SDGs) represents a milestone in international sustainability politics. The broad and ambitious agenda calls for a reconsideration of established principles and practices of sustainability governance. This article examines how the 2030 Agenda changes the notion of policy integration, which represents a fundamental principle of sustainability governance. In general, policy integration denotes forms of cross-cutting policymaking to address the complexity of real-world problems. In the context of the sustainability discourse, the concept has long been interpreted as environmental policy integration, referring to the integration of environmental concerns into other sectoral policies. Based on a review of the current SDG literature, we examine whether and how this interpretation has changed. In so doing, the reasons (why?), objects (what?) and modes (how?) of policy integration in the context of the 2030 Agenda are specified. The analysis reveals that the 2030 Agenda promotes a comprehensive, reciprocal, and complex form of goal integration which differs markedly from environmental policy integration. This novel understanding of policy integration for sustainable development calls for future research on its impact and relevance in political practice.