Background Despite guideline‐recommended use of oral anticoagulation (OAC) for stroke prevention in atrial fibrillation (AF), OAC medication adherence among patients with AF in the United States ranges from 47% to 82%. To characterize potential causes of nonadherence, we analyzed associations between community and individual social risk factors and OAC adherence for stroke prevention in AF. Methods and Results A retrospective cohort analysis of patients with AF was conducted using the IQVIA PharMetrics Plus claims data from January 2016 to June 2020, and 3‐digit ZIP code‐level social risk scores were calculated using American Community Survey and commercial data. Logistic regression models evaluated associations between community social determinants of health, community social risk scores for 5 domains (economic climate, food landscape, housing environment, transportation network, and health literacy), patient characteristics and comorbidities, and 2 adherence outcomes: persistence on OAC for 180 days and proportion of days covered ≥0.80 at 360 days. Of 28 779 patients with AF included in the study, 70.8% of patients were male, 94.6% were commercially insured, and the average patient age was 59.2 years. Multivariable regression found that greater health literacy risk was negatively associated with 180‐day persistence (odds ratio [OR]=0.80 [95% CI, 0.76–0.83]) and 360‐day proportion of days covered (OR, 0.81 [95% CI, 0.76–0.87]). Patient age and higher AF stroke risk score and AF bleeding risk scores were positively associated with both 180‐day persistence and 360‐day proportion of days covered. Conclusions Social risk domains, such as health literacy, may affect OAC adherence among patients with AF. Future studies should explore associations between social risk factors and nonadherence with greater geographic granularity.