Policymakers, practitioners and academics expect mental health and psychosocial support (MHPSS) interventions to have social outcomes. Surprisingly, the existing academic literature on the effectiveness of MHPSS has focused almost exclusively on clinical outcomes. This scoping review of 95 grey literature documents showed that social outcomes have been poorly conceptualised both theoretically and methodologically. Most reviewed documents lack definitions of theoretical concepts and measurement instruments. Mechanisms relating interventions to social outcomes have remained implicit. Further harmonisation between academic research and practice is necessary, by drawing from practice-based insights on social outcomes as found in the grey literature, and using methods and measurement instruments from social sciences in academic MHPSS research.