Background: Ovarian cancer is one of the most prevalent cancers with a high mortality rate in women. Published studies indicate that inflammation, DNA damage, and pelvic inflammatory disease (PID) are the most important risk factors for ovarian cancer and this could be induced and exacerbated by infectious agents such as Chlamydia trachomatis and Mycoplasma genitalium. The aim of this study was to determine the association between Chlamydia and Mycoplasma infections and the risk of ovarian cancer. Methods: We carried out a comprehensive search of PubMed, Scopus, Web of Science, Embase, and Google Scholar without limitation on publication date. All relevant studies which investigatived probable potential connection between Chlamydia and Mycoplasma infection and development of ovarian cancer were included. Results: Eighteen studies comprising a total of 8207 patients were evaluated in the study and this showed that the frequency of infection with Chlamydia and Mycoplasma among ovarian cancer patients was 32.6 % and 23 %, respectively. The results suggested that Chlamydia trachomatis infection increased the overall risk for ovarian cancer by 1.344 fold (OR: 1.344; 95 %CI: 1.19–1.50). Moreover, infection with Mycoplasma infections showed a week but not significant increased risk of ovarian cancer (OR: 1.12; 95 %CI: 0.86–1.44). However, the test for heterogeneity was significant among these studies. Conclusion: This study confirmed the clinical relevance of Chlamydia and Mycoplasma infection and development of the ovarian cancer risk, although the significance was marginal and study heterogeneity was significant. This highlights the need for further studies in this area.