Background: Structurally racist policies have an important impact on health. The etiologic basis of racial disparities in aggressive forms of breast cancer is not well understood. Few studies have investigated the impact of structural racism as a potential driver of etiologic heterogeneity. We sought to estimate the effect of historic redlining on the development of aggressive subtypes and late-stage disease, and examine its role in breast cancer mortality. Methods: Using the Georgia Cancer Registry, we identified 921 non-Hispanic White (NHW) and 878 non-Hispanic Black (NHB) women residing in a Georgia Home Owners' Loan Corporation (HOLC) graded area with a first primary invasive breast cancer diagnosis in 2010–2017. Historic redlining scores for 2010 census tracts were calculated according to the proportion of HOLC grades within the tract. Historic redlining scores were examined continuously and dichotomized at Citation Format: Jasmine M. Miller-Kleinhenz, Maret L. Maliniak, Micah J. Streiff, Leah Moubadder, Lauren E. Barber, Rebecca Nash, Lindsay J. Collin, Jeffrey M. Switchenko, Kevin C. Ward, Lauren E. McCullough. Historical redlining is associated with breast cancer subtype, stage at diagnosis and mortality [abstract]. In: Proceedings of the 15th AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2022 Sep 16-19; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2022;31(1 Suppl):Abstract nr C093.