BACKGROUND: In the UK, people of black Caribbean (BC) ethnicity continue to be disproportionately affected by bacterial sexually transmitted infections (STIs) and Trichomonas vaginalis (TV). We systematically reviewed evidence on the association between bacterial STIs/TV and ethnicity (BC compared to white/white British (WB)) accounting for other risk factors; and differences between these two ethnic groups in the prevalence of risk factors associated with these STIs, sexual healthcare seeking behaviours, and contextual factors influencing STI risk. METHODS: Studies presenting relevant evidence for participants aged ≥14 years and living in the UK were eligible for inclusion. A pre-defined search strategy informed by the inclusion criteria was developed. Eleven electronic databases were searched from the start date to September-October 2016. Two researchers independently screened articles, extracted data using a standardised proforma and resolved discrepancies in discussion with a third researcher. Descriptive summaries of evidence are presented. Meta-analyses were not conducted due to variation in study designs. Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines were followed. RESULTS: Of 3815 abstracts identified, 15 articles reporting quantitative data were eligible and included in the review. No qualitative studies examining contextual drivers of STI risk among people of BC ethnicity were identified. Compared to the white/WB ethnic group, the greater STI/TV risk among BCs was partially explained by variations in socio-demographic factors, sexual behaviours, and recreational drug use. The prevalence of reporting early sexual debut (<16 years), concurrency, and multiple partners was higher among BC men compared to white/WB men; however, no such differences were observed for women. People of BC ethnicity were more likely to access sexual health services than those of white/WB ethnicity. CONCLUSIONS: Further research is needed to explore other drivers of the sustained higher STI/TV prevalence among people of BC ethnicity. Developing holistic, tailored interventions that address STI risk and target people of BC ethnicity, especially men, could enhance STI prevention.