It is well established that forest conservation, restoration, and sustainable management of forests and trees outside forests can help to reduce the vulnerability of both humans and ecosystems to climate change. Yet the role of forests and trees in providing multiple goods and services that contribute to the adaptive capacity and resilience of social-ecological systems is only beginning to gain traction in climate policy and action. Climate change research and policy has overwhelmingly focused on the role of forests and trees in mitigation, neglecting the adaptation of societies that own and maintain the forests. We combined two different transformational adaptation frameworks, the Values, Rules and Knowledge framework (VRK) and the spheres of transformation framework to classify and analyse key principles and way they relate to transformational adaptation. We propose a conceptual typology of five overarching concepts and derive 10 organizing principles to address the shortcomings of current adaptation framing. The overarching concepts and key principles emphasize adaptive management, stakeholder involvement, and the need for multiple objectives, synergies and co-benefits. Various constraints are recognized, with institutional and governance barriers identified as the most severe obstacles to implementation. These key principles serve to define operational actions and guidelines specific to forests and trees for transformational adaptation. We discuss how these principles differ from more conventional sectoral and project-based approaches.