Social Return on Investment (SROI) is a methodological approach which incorporates all three aspects for evaluating interventions. Mental health problems are one of the leading causes of ill health and disability worldwide. This study aims to map existing evidence on the social value of mental health interventions that uses the SROI methodology. This scoping review is a first of its kind to focus on SROI of mental health interventions, finding a good number of SROI studies that show a positive return on investment of the identified interventions. An evidence brief has been produced outlining the key findings of the scoping review. The evidence brief highlights the social value of mental health interventions in high- and middle-income countries and outlines individual examples.