Plain Language Summary: African, Caribbean and other Black people are a priority population for HIV prevention. This research found that perceptions about HIV risk in this population do not reflect actual risk. Furthermore, HIV risk behaviours in this population are more common among individuals with higher social standing. Background: African, Caribbean and other Black (ACB) people are a priority group for HIV prevention in Canada, but little is known about the epidemiology of HIV risk in this group. Furthermore, perceptions community members and service providers have about HIV risk may not reflect the overall distribution of risk in this population. This paper compares risk perceptions to the social epidemiology of HIV risk among ACB people in London, Canada. Methods: The Black, African and Caribbean Canadian Health (BLACCH) Study is a mixed methods study that used semi-structured interviews and a cross-sectional quantitative questionnaire to collect information about HIV and health from 188 ACB people. Qualitative content analysis was used to identify themes from the interviews. Questionnaire results were weighted to more closely reflect the ACB population, and behaviours related to HIV exposure and transmission were stratified according to sex, poverty status, immigration experience and employment status. Results: Community members perceived their personal HIV risk to be low and mainly focused sexual risks. They called for more information about HIV in Canada and culturally appropriate HIV services. Service providers cited marital infidelity and cultural and religious attitudes about condoms as barriers to women protecting themselves. For men, the barriers they mentioned were cultural norms, beliefs about masculinity and underrepresentation of heterosexual ACB men at AIDS service organizations. Questionnaire results showed that HIV risk was mainly sexual. There were few differences in risk behaviours between men and women. Those living in poverty were more likely to abstain from sex (p=0.006) and use condoms (p=0.027) in the past year. Those living in Canada longer had higher prevalences of forced sex (p<0.001), mixing alcohol or drugs with sex (p=0.001) and past STI diagnoses (p=0.032). Stable employment was associated with higher prevalences of not using condoms in the past year (p=0.005) and past STI diagnoses (p=0.018). Conclusions: The results show that perceptions about ACB people’s HIV risk differ from actual risk, and those with higher social standing might be at greater risk. Furthermore, the social determinants of health are important epidemiologic factors within the ACB population, and prevention interventions for this population must account for them.