Most individuals in both developing and developed countries who experience mental illness do not receive psychological services. The dominant model of delivering services used in developed countries (individual therapy by a highly trained mental health professional) can provide effective (i.e., evidence-based) treatments but is greatly limited as a means of reaching the large swath of individuals in need. We highlight several models outside the mental health professions (e.g., public health, medicine, business) that are more affordable and accessible and can be scaled up to reach many individuals in need. These models include task shifting, disruptive innovations, interventions in everyday settings, best-buy interventions, lifestyle changes, and social media. We convey their key characteristics and how they have been or can be applied to mental health. We end by discussing challenges in applying the models, critical issues on which effective treatment delivery depends, and paths to make progress.