Purpose: Sustainability transitions (STs) refer to large-scale step changes in complex systems required to face sustainability issues. We aim to delineate how they can unfold in service ecosystems, especially when inspired by regenerative thinking. Design/methodology/approach: We develop a conceptual framework based on a processual view of STs and provide a propositional inventory based on literature leveraging deductive reasoning. Moreover, we contextualize our conceptualizations by showing illustrative examples of cities coping with STs. Findings: We connect the perception of unsustainability with the shift toward service-dominant (S-D) logic and identify them as triggers of an ST; we focus on the role of nested service ecosystems and the adoption of regenerative thinking in STs; finally, we highlight the domino effect that can drive continuous change towards sustainability in service ecosystems. Future research could be focused on (loss of) sensemaking for driving STs, practical approaches to deal with institutional tensions in nested service ecosystems and the possible fractality of ST processes in service ecosystems. Originality/value: This study supports the understanding of STs in cities and other systems such as industries, markets and organizations. It contributes to ST literature by suggesting the adoption of S-D logic and system lenses to identify, drive and cope with system changes toward sustainability, showing implications for policymakers and practitioners. Furthermore, it contributes to S-D logic by unfolding the self-adjustment of service ecosystems and the focus of sustainability initiatives on nested service ecosystems to sustain the broader systems. Finally, it contributes to transformative service research by identifying how the procedural and inspirational principles characterizing regenerative thinking can support design for STs. © 2024, Emerald Publishing Limited.