Background The perinatal period is a time of increased vulnerability to mental health problems, however, only a small proportion of women seek help. Poor mental health literacy (MHL) is a major barrier to seeking help for mental health problems. This study aimed to collect the existing evidence of MHL associated with perinatal mental health problems (PMHP) among perinatal women and the public. This review analysed which tools were used to assess perinatal MHL as well as the findings concerning individual components of perinatal MHL. Methods Four electronic databases (PubMed, PsycINFO, Web of Science, and CINAHL) were analysed from their inception until September 1, 2020. Not only quantitative studies reporting on components of MHL (knowledge, attitudes, and help-seeking), but also studies reporting overall levels of MHL relating to PMHP were taken into account. Two independent reviewers were involved in the screening and extraction process and data were analysed descriptively. Results Thirty-eight of the 13,676 retrieved articles satisfied the inclusion criteria. The majority of selected studies examined MHL related to PMHP in perinatal women (N = 28). The most frequently examined component of MHL in the selected data set was help-seeking. A lack of uniformity in assessing MHL components was found. The most common focus of these studies was postpartum depression. It was found that the ability to recognize PMHP and to identify relevant symptoms was lacking among both perinatal women and the public. Perinatal women had low intentions of seeking help for PMHP and preferred seeking help from informal sources while reporting a variety of structural and personal barriers to seeking help. Stigmatizing attitudes associated with PMHP were found among the public. Conclusions There is a need for educational campaigns and interventions to improve perinatal MHL in perinatal women and the public as a whole.