Purpose: Working mothers are at greater risk for postpartum depression. Maternity leave characteristics, including length, wage replacement and employment protection, could have relevant implications for mothers’ mental health. We propose to explore whether there is an association between maternity leave characteristics and postpartum depression. Methods: We conducted a systematic review searching for randomized controlled trials, quasi-experimental, cohort or cross-sectional studies on five databases using search terms including maternity and parental leave and depression, as well as references in relevant articles. We identified 500 articles and included 23 of those. We used the EPHPP Quality Assessment Tool for Quantitative Studies to assess the quality of the studies. Results: Paid and longer maternity leaves tend to be associated with a reduction of postpartum depression symptoms in high-income countries. No studies explored the association between employment protection and postpartum depression. The quality of studies ranged from strong to weak, mostly influenced by study design. Conclusion: More restrictive maternity leave policies tend to be associated with higher rates of postpartum depression, although more research needs to be conducted in the Global South.