Abstract Body (Do not enter title and authors here): Background: Despite being one of the most diverse cities in the United States, Chicago is also notably segregated. The distinct separation among its 77 communities provides an opportunity to examine racial and ethnic segregation and the impact of social determinants of health (SDOH) on health outcomes. Research Question: How do race/ethnicity and SDOH influence hypertension (HTN) prevalence? Aim: To examine the relationships between race/ethnicity, SDOH, and HTN prevalence at the community level. Methods: This cross-sectional study used data from the Chicago Health Atlas collected between 2021 and 2022. The sample included data from all 77 Chicago communities and 2,738,956 of its residents. Two-step latent profile analyses were performed to classify each of the community according to the predominant race/ethnicity of its residents (Asian, Black, Hispanic, or White) and SDOH level (low, moderate, high), which was defined as how favorable the physical and social conditions are within the community and determined using 14 indicators (Table 1). Kruskal-Wallis tests were used to compare the prevalence of HTN among the communities by predominant race/ethnicity and SDOH level. Results: Among the 77 communities, 28 were predominantly Black, 27 were predominantly White, 21 were predominantly Hispanic, and 1 was predominantly Asian. HTN prevalence was highest in predominantly Black communities (39.9%), then the Asian community (35.8%), Hispanic communities (28.8%), and White communities (25.2%), p<.001. Based on the 14 SDOH indicators, 26 of the communities were classified as low SDOH (unfavorable conditions), 25 as moderate SDOH (moderately favorable), and 26 as high SDOH (favorable). HTN prevalence was highest in low SDOH communities (36.3%), followed by moderate SDOH communities (31.4%), and lowest in high SDOH communities (27.2%), p=.003. Conclusions: The findings highlight significant disparities in HTN prevalence across Chicago's communities, with higher rates observed in predominantly Black and low SDOH areas. These results underscore the need for targeted public health interventions to address the intersection of racial/ethnic segregation and SDOH.