The prevalence of mental health disorders and suicide amongst agricultural producers is a global problem. Community leaders, researchers, policymakers, and clinicians have mobilized to develop programs to address this issue. This study reviewed a wide range of mental health interventions targeting farmer mental health spanning over 50 years and examined their reported effectiveness and constraints. A total of ninety-two articles on farmer mental health were included in a final systematic review. Most articles were written concerning mental health literacy and peer and paraprofessional support interventions in the United States and Australia. Among the 56 studies reporting empirical evaluative data, 21 were mixed-method, 20 quantitative, 11 qualitative, and 5 literature synthesis. Non-experimental, self-reported, and qualitative data suggest efficacy of mental health literacy programs, peer and paraprofessional support, and community-based and agroecological interventions. However, most interventions were not subject to rigorous evaluation and only one intervention was evaluated using a control condition. The heterogeneity of existing studies and paucity of rigorous evaluation proscribes firm conclusions related to program-type efficacy. This review demonstrates that there is still a need for a stronger and broader evidence base in the field of farmer mental health interventions, which should focus on both holistic, multi-component programs and targeted approaches.