This study examines the association between individual- and area-level social determinants of health (SDOH) and the risk of atherosclerotic cardiovascular disease (ASCVD) in a cohort of 26,316 participants from four large US cohort studies. The primary outcome was the time to the first incident ASCVD event, defined as a composite of nonfatal myocardial infarction, death from coronary heart disease, and fatal or nonfatal stroke. Individual- and area-level SDOH, including education, income, and employment status, were assessed. The study found that low education, low income, and unemployment at both individual and area levels were associated with an increased risk of incident ASCVD events. Adding area-level SDOH alone to the Pooled Cohort Equations (PCEs) did not improve model discrimination but modestly improved calibration. Adding both individual- and area-level SDOH to the PCEs led to a modest improvement in both discrimination and calibration, particularly in non-Hispanic Black individuals. Additionally, adding individual-level SDOH to the Predicting Risk of CVD Events (PREVENT) plus Social Deprivation Index (SDI) equations modestly improved calibration in non-Hispanic Black and White individuals. These findings suggest that both individual- and area-level SDOH should be considered in future development of ASCVD risk assessment tools, especially for non-Hispanic Black individuals.This study examines the association between individual- and area-level social determinants of health (SDOH) and the risk of atherosclerotic cardiovascular disease (ASCVD) in a cohort of 26,316 participants from four large US cohort studies. The primary outcome was the time to the first incident ASCVD event, defined as a composite of nonfatal myocardial infarction, death from coronary heart disease, and fatal or nonfatal stroke. Individual- and area-level SDOH, including education, income, and employment status, were assessed. The study found that low education, low income, and unemployment at both individual and area levels were associated with an increased risk of incident ASCVD events. Adding area-level SDOH alone to the Pooled Cohort Equations (PCEs) did not improve model discrimination but modestly improved calibration. Adding both individual- and area-level SDOH to the PCEs led to a modest improvement in both discrimination and calibration, particularly in non-Hispanic Black individuals. Additionally, adding individual-level SDOH to the Predicting Risk of CVD Events (PREVENT) plus Social Deprivation Index (SDI) equations modestly improved calibration in non-Hispanic Black and White individuals. These findings suggest that both individual- and area-level SDOH should be considered in future development of ASCVD risk assessment tools, especially for non-Hispanic Black individuals.