The increasing prevalence of mental health issues is a global concern, and implementing low-cost, effective, population-level interventions is critical. Physical activity interventions, including climbing, hold promise as one way to bridge this gap. Climbing is a non-mainstream form of physical activity that is gaining popularity and is being increasingly investigated as a potential mental health intervention, with promising findings. As this field of enquiry grows, the range in methods, intervention components, outcome measures, and participant characteristics is increasing, making cross-study comparisons challenging. There is a need to characterise the literature and identify common methods and gaps in knowledge. PsycInfo, CINAHL, Web Of Science, Embase, MEDline, Scopus, SportDISCUS were searched for studies including climbing and a measure of mental health or wellbeing. CENTRAL and clinicaltrials.gov were searched for ongoing trials. All study designs were eligible for inclusion. Grey literature and reviews were excluded. All screening, data extraction, and quality assessments occurred in duplicate. A narrative synthesis was conducted. Fifty-nine papers were eligible for inclusion, covering a wide range of study designs (interventions, experimental studies, descriptive studies, qualitative and mixed-methods studies), contexts, and samples (clinical/non-clinical, climbers/non-climbers, adults/children and adolescents). Overall, climbing interventions and participation seemed to have benefits for mental health and wellbeing across a range of individuals. It is unclear what the mechanisms leading to these benefits might be. Further high quality research is warranted to investigate exactly how, where, when, and for who climbing can improve mental health and wellbeing, and to investigate theories of change.