Rates of both violent victimization and violence perpetration are known to be elevated among individuals with mental illness compared with those in the general population, though the relative risk of each outcome is less well established. In this systematic review, PubMed, Embase, Web of Science, PsycINFO, and Criminal Justice Abstracts were searched for articles published any time before October 2021 that reported the prevalence or incidence of both violent victimization and perpetration. We performed two searches to identify studies using samples or cohorts of (1) persons with mental illnesses and (2) persons in the general population. A total of 25 studies (9 examining persons with mental illnesses, 13 examining persons in the general population, and 3 examining both sample/cohort types) were identified and data was extracted to describe the type and size of cohort or sample, definitions and terminology (i.e., mental illness, violence victimization, violence perpetration), data source(s), observation period, prevalence/incidence of victimization, and prevalence/incidence of perpetration. The Joanna Briggs Institute Critical Appraisal Checklist for Studies Reporting Prevalence Data was used to conduct a quality assessment of all included studies. Due to marked study heterogeneity, results were presented using a narrative synthesis approach. Across studies, findings were mixed, and the methodological approaches varied greatly. Broadly, the review provides evidence for (1) higher rates of victimization than perpetration for both individuals with mental illness and those in the general population and (2) higher rates of both victimization and perpetration for those with mental illness compared to those in the general population.