Objective Most Black individuals in Canada report having experienced racial discrimination. Although previous studies have shown that there is a strong relationship between racial discrimination and posttraumatic stress disorder (PTSD), no studies in Canada have documented this association among Black individuals. The present study documents (1) the prevalence of PTSD among Black individuals using data from the Black Communities Mental Health project and (2) risk factors associated with PTSD, including racial microaggressions, everyday racial discrimination, and internalized racism. Method A total of 860 participants (75.6% of women) aged 15 to 40 years old ( M = 24.96, SD = 6.29) completed questionnaires assessing PTSD, experience of traumatic events, racial microaggressions, everyday racial discrimination, and internalized racism. Results Findings showed that 95.1% of participants reported exposure to at least one traumatic event during their lifetime. In total, 67.11% of participants reported probable PTSD with no significant difference between men and women (68.2% and 67.8%, χ2 = 0.132, p = 0.72). Participants born in Canada were more likely to experience significant PTSD symptoms, compared to those born abroad (70.92% and 53.14% , χ2 = 19.69, p < 0.001). A multivariable linear regression model of PTSD symptoms was computed using sociodemographic variables and exposure to traumatic events as independent variables, which explained 25.9% of the variance. In addition to these variables, a second model included racial microaggressions, everyday racial microaggressions, and internalized racism, which explained 51.8% of the variance. The model showed that traumatic events ( b = 0.6; p = 0.02), racial microaggressions ( b = 0.5; p < 0.001), everyday discrimination ( b = 0.2; p = 0.03) and internalized racism ( b = 0.5; p < 0.001) were positively associated with PTSD symptoms. Conclusions This article highlights the detrimental consequences of racial discrimination against Black people in Canada. Prevention and mental health programs aimed at mitigating its consequences on the lives of Black people and other racialized populations must be implemented.