Background: Polycystic ovary syndrome (PCOS) affects reproductive-aged women and is associated with increased prevalence of serious clinical problems including: reproductive implications, metabolic dysfunction, and cardiovascular risk. Physical activity offers several health benefits for women with PCOS. The aim of this systematic review was to synthesize evidence on the effect of different types of exercise on reproductive function and body composition for women with PCOS. Methods: This was a systematic review and meta-analysis of randomized controlled trials (RCTs) following recommended review methods. We searched 6 databases: Cumulative Index of Nursing and Allied Health Literature; Embase; MEDLINE (via Ovid); PubMed; Sport Discus; and Web of Science; and we developed search strategies using a combination of Medical Subject Headings terms and text words related to exercise interventions for women with PCOS. There was no restriction on language or publication year. The search was conducted on April 16, 2019 and updated on November 15, 2019. Two authors independently screened citations, determined risk of bias and quality of evidence with Grading of Recommendations Assessment, Development and Evaluation. We conducted meta-analyses following recommended guidelines, and report results using standardized mean difference (SMD). Results: Ten RCTs (n = 533) were included in this review. Studies tested the following interventions: aerobic, resistance, and combined (aerobic/resistance) training programs. Most studies were small (average 32, range 15-124 participants), and of relatively short duration (8-32 weeks). There was high heterogeneity for outcomes of reproductive function (menstrual cycle, ovulation, and fertility). We noted low certainty evidence for little to no effect of exercise on reproductive hormones and moderate certainty evidence that aerobic exercise reduced body mass index (BMI) in women with PCOS: BMI SMD -0.35, 95% confidence interval -0.56 to -0.14, P = .001. Conclusion: For women with PCOS, evidence is limited to discern the effect of exercise on major health outcomes (e.g., reproductive function). There is moderate certainty evidence that aerobic exercise alone is beneficial for reducing BMI in women with PCOS. Future studies should be conducted with longer duration, larger sample sizes, and should provide detailed information on menstrual cycle and fertility outcomes.PROSPERO Systematic review registration: 2017 CRD42017058869.