Introduction Maternal mental health disorders such as anxiety and depression are major public health concerns. Evidence shows a link between maternal mental health disorders and preterm birth and low birth weight. However, the impacts of maternal mental health disorders on stillbirth and infant mortality have been less investigated and inconsistent findings have been reported. Thus, using the available literature, we plan to examine whether prenatal maternal mental health disorders impact the risk of stillbirth and infant mortality. Methods and analysis This systematic review and meta-analysis will adhere to Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines and will be registered with the International Prospective Register of Systematic Reviews. Systematic searches will be conducted (from database inception to December 2019) in Medline, Embase, PsycINFO and Scopus for studies examining the association of prenatal mental health disorders and stillbirth and infant mortality. The search will be limited to studies published in English language and in humans only, with no restriction on the year of publication. Two independent reviewers will evaluate records and assess the quality of individual studies. The Newcastle-Ottawa scales and GRADE (Grading of Recommendations, Assessment, Development and Evaluations) approach will be used to assess the methodological quality and bias of the included studies. In addition to a narrative synthesis, a random-effects meta-analysis will be conducted when sufficient data are available. I 2 statistics will be used to assess between-study heterogeneity in the estimated effect size. Ethics and dissemination As it will be a systematic review and meta-analysis based on previously published evidence, there will be no requirement for ethical approval. Findings will be published in a peer-reviewed journal and will be presented at various conferences. PROSPERO registration number 159834.