Introduction: Racial and social disparities affect cancer and CVD-related mortality. The relationship between social vulnerability and concomitant cancer and CVD (cardio-oncology) related mortality remains understudied. Methods: We used the CDC Wide-Ranging OnLine Data for Epidemiologic Research (WONDER) database to determine the association between deaths attributed to the presence of concomitant CVD and cancer (ICD-10 codes I00-I09, I11, I13, I20-I51 and C00-C96), and the county-level social-vulnerability index (SVI). SVI measures a community’s vulnerability based on socioeconomic status, household composition, disability, minority status, language, and transportation. We aggregated counties by SVI quartiles (1st: most favorable = 0.00 to 0.25; 4th: least favorable = 0.75 to 1.00) and compared age-adjusted mortality rates (AAMRs) across SVI quartiles. Results: Between 2014 and 2018, the AAMR due to concomitant cancer and CVD was 47.75 (95% CI, 47.66- 47.85) per 100,000 person-years with higher mortality in areas with a higher SVI (Figure). Similarly, CVD and cancer-related mortality was also significantly greater in counties with the highest SVI [(CVD: 1.287 (95% CI 1.284-1.290); Cancer: 1.087 (95% CI 1.084-1.091)]. Moreover, the proportional increase in cardio-oncology mortality between the highest and lowest SVI counties was greater than that observed for CVD or cancer-associated mortality alone (p<0.001). This difference was most striking in adults < 45 years, females, Asian and Pacific Islanders, and Hispanics. Conclusion: A graded increase in cardio-oncology mortality is observed in counties with higher social vulnerability. The incremental impact of SVI was greater for cardio-oncology mortality than for cancer or CVD mortality alone, particularly in certain demographic groups. These findings highlight the need for targeted resource allocation and public health interventions to address social inequities in cardio-oncology.