This synthesis article conceptualizes transformative climate actions (TCAs) by reviewing social-science-based climate and transformation research, with a particular focus on (Western) sufficiency literature. It identifies six key characteristics of TCAs. First, they aim to transform social practices and provisioning systems to reshape society-nature relations, requiring a ‘whole-of-government’ approach and state capacity building for cross-sectoral coordination. Second, TCAs prioritize sufficiency, using efficiency and substitution as supporting strategies rather than parallel goals. Third, they empower collective agency, shifting the focus from individual behaviour changes to societal structures. Fourth, they presuppose a shift toward a multi-level planning framework that moves beyond market-based governance, integrating top-down steering with bottom-up, reflexive deliberation and experimentation. Fifth, TCAs recognize the distributional character of ecological crises, ensuring universal access to essential provisioning while curbing excess production and consumption through eco-social policy portfolios. Finally, they rely on broad alliances of diverse actors, grounded in everyday interests, with empowered multi-stakeholder platforms to challenge entrenched interests. In developing these six characteristics, the article bridges conceptual debates with real-world policymaking, highlighting key climate policy challenges while demonstrating how integrating these characteristics can drive deep societal transformations and support policymakers in designing holistic strategies for effective climate action.