Arts engagement is a positive health behavior that could support the wellbeing of aging populations globally. However, research to date is predominantly from Western countries, leaving it unclear whether arts engagement can support wellbeing in Japan, where arts are differently valued and engaged with. There is also a social gradient in both arts and cultural engagement and wellbeing that may have led to an overestimation of the impact of participation on wellbeing in Western countries. We therefore tested whether participation in community arts and cultural groups was associated with subjective and social wellbeing after removing confounding by demographic, socioeconomic, and health-related factors in Japan and England. We harmonized longitudinal data from the Japan Gerontological Evaluation Study (JAGES) 2016 and 2019 waves and the English Longitudinal Study of Ageing (ELSA) 2014 and 2018 waves to enable cross-country comparisons. We included 9,511 adults aged 65 and over from JAGES and 3,133 participants aged 65 and over from ELSA. Using inverse probability weighted regression adjustment, we estimated the causal effect of participating in arts and cultural groups on subsequent life satisfaction, happiness, and depressive symptoms (subjective wellbeing) as well as social support (social wellbeing). In JAGES, arts and cultural group participation was associated with higher odds of life satisfaction and higher social support scores. In the ELSA sample aged 65 and over, group participation was only associated with higher depressive symptoms. However, in the full ELSA sample aged 50 and over, this association was no longer present. Instead, group participation was associated with higher social support scores. Our findings indicate that arts and cultural group participation can enhance life satisfaction and social wellbeing in Japan, perhaps with more consistent benefits than in England. Facilitating participation in arts and cultural groups could help older adults to maintain a healthy social support network, which could further support their health as they age.