Aims The aim of this study was to investigate the effect of music intervention on breast milk production in breastfeeding mothers. Design A systematic review and meta-analysis of randomized controlled trials following Cochrane methods were conducted. Data Sources We performed a literature search in Web of Science, Science Direct, PubMed, MEDLINE, Cochrane Library, CINAHL, the Networked Digital Library of Theses & Dissertations, Ovid and ProQuest without year limitation. The review period covered January 1978-March 2020. Review Methods Two independent researchers screened the literature using specific keywords and selected randomized controlled trials based on the inclusion and exclusion criteria according to the PICOS criteria. Result Of 2,081 randomized controlled trials, 5 were included in this systematic review and meta-analysis. The total sample of the five trials was 554 participants. Active and passive music lasting 11-60 min was played in 1-14 sessions. No publication bias was noted. Cochran's Q test results pointed to a low level of heterogeneity among the randomized controlled trials. Overall, the results showed that music intervention had a low and positive effect on breast milk production in breastfeeding mothers. Conclusion A systematic review and meta-analysis conducted on five trials showed that music can be an effective way to increase breast milk production. Impact This systematic review and meta-analysis investigated the effect of music on breast milk production in breastfeeding mothers and found sound evidence supporting its positive effects. Nurses, academics, mothers, and their children and society can benefit from these results. Nurses who give counselling to breastfeeding mothers can use music intervention to help them increase breast milk production.