Abstract: Background: Digital Behavior Change Interventions (DBCIs) offer substantial potential to widely disseminate prevention and health promotion content. One key issue remains the absence of high-quality evidence of the effects of DBCIs for long-term health outcomes and unintended consequences. Here, we argue that in addition to better-quality evidence for effects on health, a more consideration of unintended consequences of DBCIs on multiple levels is warranted. Objectives: We suggest a multilevel perspective on unintended consequences of DBCIs building on a socio-ecological understanding of health promotion and prevention. Methods: Narrative literature review. Results: Unintended consequences of DBCIs can be located on the level of the individual engaging with DBCIs, on a level of social interactions, and on the level of health services, in multiple domains from health-related, behavior modification, affective aspects to data privacy and financial implications. Implications: Our proposed social–ecological perspective improves the classification of unintended consequences of DBCIs. This could facilitate building a cumulative evidence base to support the development of more effective and inclusive DBCIs.