This study investigates the impact of forest-activity diversity on life satisfaction using data from the 2023 Forest Recreation and Welfare Activities Survey conducted by the Korea Forest Service. Forest-activity diversity was categorized into two dimensions: experience diversity (combining forest recreation and welfare-activity experiences) and utilization diversity (the use of forest recreation and welfare facilities and programs). Hierarchical regression analysis revealed that greater diversity in forest activities and utilization significantly enhances life satisfaction. However, participants who engaged in both forest recreation and welfare activities or utilized both facilities and programs reported comparatively lower life satisfaction. The findings indicate that while activity and utilization diversity are critical in improving life satisfaction, the benefits may plateau with excessive participation. The effects of leisure activities also vary based on individual factors such as age, gender, and life context, underscoring the importance of tailored forest welfare programs. Balanced and meaningful engagement in diverse activities is essential for maximizing well-being. While forest activities generally enhance life satisfaction, programs must be inclusive and flexible to address diverse user needs. Future research should incorporate objective measures and longitudinal designs to better evaluate the long-term effects of forest welfare activities.