Background Physical activity (PA) is consistently linked to mental health outcomes. Purpose This meta-analysis synthesized depressive symptom outcomes of supervised and unsupervised PA interventions among healthy adults. Methods Comprehensive searching and coding were applied to PA interventions among adults without clinical depression. Analyses included random-effects standardized means, Q, and moderator analysis using analysis of variance and regression meta-analytic analogues. Results Treatment versus control comparisons yielded a standardized mean effect size of 0.372 among 38 supervised PA studies and 0.522 among 22 unsupervised PA studies. Preliminary moderator analyses suggested that supervised PA interventions may be more effective when they include flexibility/resistance and low-intensity exercise. Unsupervised PA interventions may be more effective when they recommend center-based PA. Methodological moderators (random assignment, control group management) were identified. Conclusions These findings document that PA interventions reduce depressive symptoms even in adults without clinical depression. Moderator analyses suggest directions for future research as well as practice.