Introduction: Some evidence indicates that breastfeeding could offer protection in case of postnatal depression and support recovery from symptoms. This study investigates the relationship to identify which practices and forms of support prove beneficial. Materials and methods: Literature search was carried out in databases, such as Cochrane, EBSCOhost, EMBASE, ProQuest, PubMed, and Science Direct from 2013 to recent years. The criteria for inclusion are: (1) Randomized controlled trial or observational studies; (2) Study population, postpartum women at risk or having symptoms of postpartum depression (PPD); (3) Intervention, breastfeeding practice or breastfeeding support; (4) Comparison, women without breastfeeding practices or breastfeeding support; (5) Outcome, severity of PPD.Results: Nineteen studies were included in this review; 5 studies about breastfeeding practices and 14 studies about breastfeeding support. These studies were conducted in 11 countries, included a total of 79,303 participants. Breastfeeding exclusivity, duration, satisfaction, and early initiation contributed to the reduction of PPD severity. Breastfeeding educational (MD = -0.59 [95% CI, -0.62, -0.56]; p < 0.01), psychosocial (MD = -2.85 [95% CI, -4.03, -1.68]; p < 0.01; I 2 = 0%), and medication support (MD -1.66 [95% CI, -2.48, -0.83], p = 0.38; I 2 = 0%) reduced the severity of PPD. Moreover, educational support also decreases the risk of developing PPD (RR 0.84 [95% CI, 0.71-1.00], p = 0.05; I 2 = 20%). Conclusion: Breastfeeding practices have been shown to diminish the grading of PPD and serve as a preventive measure against the risk of depressive symptoms throughout the postpartum period. Additionally, breastfeeding support has been found to alleviate the severity of postnatal depression. It is worth noting that psychosocial support is recommended in this regard, further underscoring the importance of holistic support systems for new mothers. Therefore, early initiation of exclusive breastfeeding and maintaining mother satisfaction are beneficial to be encouraged and educated since pregnancy. Clinical significance: Breastfeeding has a vital role in reducing the severity of PPD and preventing the symptoms after childbirth. Supporting mothers through education and encouragement to start breastfeeding since pregnancy proves the importance of providing holistic care for mothers.