OBJECTIVE Our aim was to identify risk factors for sight-threatening diabetic retinopathy (STDR) in a multiethnic cohort of type 2 diabetes attending a surveillance digital diabetes eye screening service in South London between 2004 and 2018. RESEARCH DESIGN AND METHODS A total of 8,529 people who had no retinopathy at baseline were included in this analysis. Female participants made up 49% of the cohort, 38% were White Caucasian, 43.4% were African Caribbean, and 18.6% were of other racial/ethnic groups. STDR was defined as the presence of any moderate to severe nonproliferative or preproliferative diabetic retinopathy, proliferative diabetic retinopathy, or maculopathy in either eye, per U.K. National Diabetic Eye Screening criteria. Multivariable analyses with STDR as the primary end point and death as a competing event were performed. RESULTS Of the 8,529 people in the cohort, 489 (5.7%) progressed to STDR over a median follow-up of 8.9 years. They had higher baseline median (interquartile range) HbA 1c values (75.9 [58.4, 93.4] vs. 61.7 [49.9, 79.2] mmol/mol) and longer duration of diabetes (11 [7, 15] vs. 4 [2, 9]) years and were more likely to be of African Caribbean heritage (48% vs. 52%; P < 0.001 for all). Given that 2,880 people died before progressing to STDR, we performed a competing risk analysis, in which African Caribbean ethnicity (hazard ratio [HR] 1.35; 95% CI 1.13–1.62), duration of diabetes (HR 1.05, 95% CI 1.05–1.06), HbA 1c (HR 1.02; 95% CI 1.02-1.02), and total cholesterol (HR 1.13; 95% CI 1.05–1.21) emerged as significant independent factors associated with development of STDR. CONCLUSIONS In a multiethnic cohort of type 2 diabetes, we observed an increased risk of STDR in people of African Caribbean ethnicity, which was independent of traditional risk factors.