The aim of this narrative review is to explore whether nature-based interventions improved individual public health outcomes and health behaviours, using a conceptual framework that included pathways and pathway domains, mechanisms, and behaviour change techniques derived from environmental social science theory and health behaviour change models. A two-stage scoping methodology was used to identified studies published between 2000 and 2021. Peer reviewed, English-language reports of nature-based interventions with adults (N = 9) were included if the study met the definition of a health–behaviour change intervention and reported at least one measured physical/mental health outcome. Interventions focused on the restoring or building capacities pathway domains as part of the nature contact/experience pathway; varied health behaviour change mechanisms and techniques were present but environmental social-science-derived mechanisms to influence health outcomes were used less. Practical recommendations for future interventions include explicit statement of the targeted level of causation, as well as utilisation of both environmental social science and health behaviour change theories and varied public health outcomes to allow simultaneously testing of theoretical predictions.