Background: The Black population in the US constitutes of 4 million immigrants, with 50% from the Caribbean. It has been shown that breast cancer is responsible for 14%-30% of cancer deaths in the Caribbean; this is up to two times higher than the USA. Methods: Retrospective cohort of 1369 self-identified Black women with breast cancer. Data was obtained from Jackson Memorial Health Systems and University of Miami Health System Tumor Registry. Individual-level data from 1132 cases was used to estimate hazard rations (HRs) of women born in the Caribbean (CB) or in the USA (USB) using Cox proportional hazards regression analysis for overall survival. Median follow-up was 115 months (interquartile range, 91.9-138.1 months) per participant. Results: Data from 622 (54.9%) USB women and 507 (45%) CB women diagnosed with breast cancer between 2006-2017. 90% (n = 1232) of the cohort is of non-Hispanic ethnicity. Caribbean immigrants from Haiti (18.3%), Jamaica (6.5%), Bahamas (3.1%), Cuba and Dominica Republic (2.8% each), Trinidad and Tobago (1%) and other nationalities from the Organization of Eastern Caribbean States were included, mean age 55.7 [95% CI, 54.7-56.8]; USB mean age 57.6 [95% CI, 56.4-58.7] (P = 0.02). Compared to USB, CB had lower BMI at diagnosis 29.6 [95% CI, 28.9-30.3] versus 30.9 [95% CI, 30.1-31.7, P = 0.015]. Compared to CB patients, USB patients had more ER- [31.4% vs 39.1 %, P = 0.018] and triple negative breast cancers [19.6% vs 27.9%, P = 0.003]. Compared to USB patients, CB presented at more advanced stage, III and IV [44.2% vs 35.2%], p = 0.016. In spite of higher advanced stage at diagnoses, CB patients had a better breast cancer overall survival [HR = 0.75; 95%CI, 0.59-0.96; P = 0.024]. Black Hispanic patients had a better overall survival [HR = 0.51; 95%CI, 0.28-0.93; p = 0.028] compared to non-Hispanic Blacks. Compared to Hispanic Caribbean, non-Hispanic Caribbean had a worse overall survival [HR = 1.98; 95%CI, 1.00-3.94; P = 0.048]. The distribution of patients treated at the private cancer center and the safety net hospital were the same, differences in outcomes observed are due to intrinsic differences. Conclusions: This is the largest analysis to date of self-identified Black breast cancer patients in the context of nativity, race, ethnic identity and overall survival with clinico-pathologic characteristics. CB immigrants diagnosed with breast cancer have a better overall survival than US born Black patients. This finding suggests that within the African diaspora in the USA, additional factors beyond race contribute to the outcomes.