Introduction: Trauma related to service in the military and emergency services is exceptionally high. Nature-based social prescriptions (non-traditional therapeutic interventions that utilise natural settings and social connection) provide an alternative to standard therapy approaches, such as cognitive behaviour therapy, which may not meet the complex needs of military and emergency personnel with trauma experiences. This systematic review evaluates nature-based social prescriptions to improve this population's social, emotional, and psychological wellbeing. Methods: Studies published up to June 2024 in nine databases were identified using search terms related to military and emergency responders, stress disorders, and nature-based interventions. Interventions not specifically utilising nature were excluded as they have been reviewed elsewhere. Results: Twelve studies met inclusion criteria and were evaluated: two randomised controlled trials, two non-randomised trials, and eight pre-post evaluations. Programs ranged in ‘dose’ from 16 to 205 hours (M = 72.58 hours) across 2 to 30 days (M = 7.70 days). They produced effect sizes for PTSD symptoms in the medium to large range (Hedges’ g = 0.49 to 2.70, M = 1.10), depression in the medium to large range (Hedges’ g = 0.38 to 2.75, M = 0.87), anxiety in the medium to large range (Hedges’ g = 0.56 to 3.42, M = 1.16), and stress in the medium to large range (Hedges’ g = 0.46 to 1.57, M = 0.93). Limitations: Risks of bias were found, meaning the findings should be interpreted with care. Conclusion: These findings indicate that nature-based social prescriptions are promising adjunctive or stand-alone treatments to reduce treatment hesitancy, improve access, and manage trauma-related symptoms in military and emergency responder populations.