Mental ill health accounts for 13 per cent of total global disease burden with predictions that depression alone will be the leading cause of disease burden globally by 2030. Poor mental health is consistently associated with deprivation, low income, unemployment, poor education, poorer physical health and increased health-risk behaviour. A plethora of research has examined the relationship between physical activity and mental wellbeing; however, the influence of community-wide gamification-based physical activity interventions on mental wellbeing, to the authors' knowledge, is yet to be explored. In view of this paucity of attention, the current study examined the relationship between physical activity and mental wellbeing pre/post a community-wide, gamification-based intervention. The findings revealed that increases in mental wellbeing were significantly greater for the least active prior to the intervention, and a strong, positive correlation between increase in physical activity and increase in mental wellbeing was observed.