This meta-analysis examines the effectiveness of positive psychology interventions (PPIs) in enhancing subjective well-being, psychological well-being, and reducing depressive symptoms among the general public and individuals with specific psychosocial problems. The study included 40 articles describing 39 studies with a total of 6,139 participants. The standardized mean differences for subjective well-being, psychological well-being, and depression were 0.34, 0.20, and 0.23, respectively, indicating small effects. Follow-up effects at three to six months showed small but significant improvements in subjective well-being and psychological well-being, suggesting sustainability. Heterogeneity was high due to the diverse nature of the studies. Several factors moderated the impact on depression, including intervention duration, recruitment methods, and study quality. Publication bias was indicated, and the quality of studies varied. The findings suggest that PPIs can effectively enhance well-being and reduce depressive symptoms, but more high-quality, diverse studies are needed to strengthen the evidence base.This meta-analysis examines the effectiveness of positive psychology interventions (PPIs) in enhancing subjective well-being, psychological well-being, and reducing depressive symptoms among the general public and individuals with specific psychosocial problems. The study included 40 articles describing 39 studies with a total of 6,139 participants. The standardized mean differences for subjective well-being, psychological well-being, and depression were 0.34, 0.20, and 0.23, respectively, indicating small effects. Follow-up effects at three to six months showed small but significant improvements in subjective well-being and psychological well-being, suggesting sustainability. Heterogeneity was high due to the diverse nature of the studies. Several factors moderated the impact on depression, including intervention duration, recruitment methods, and study quality. Publication bias was indicated, and the quality of studies varied. The findings suggest that PPIs can effectively enhance well-being and reduce depressive symptoms, but more high-quality, diverse studies are needed to strengthen the evidence base.