The purpose of this dissertation is to investigate the role of personality as a predictor of successful aging. Three studies are presented and discussed using the data from the Georgia Centenarian Study (Study 1 and 3) and the data from the Midlife in the United States study (Study 3). Study 1 suggested an alternative approach for measuring the Big Five personality domains, Digman’s (1997) two higher-order personality factors (i.e., Alpha and Beta), and found a positive association between personality and each component of successful aging (i.e., cognitive functioning, physical functioning, physical health, and social engagement). Study 2 examined the longitudinal effects of personality level and personality change on successful aging and found that higher initial levels of personality traits (i.e., emotional stability, extraversion, openness to experience, conscientiousness, and agreeableness) were positively associated with successful aging and that decreases in each personality trait over time predicted worse outcomes of successful aging. Finally, based on the developmental adaptation model, Study 3 examined the effects of cumulative life events and personality on objective and subjective successful aging, along with the mediating effects of personality on the relationship between cumulative life events and successful aging. The findings of the three studies support previous studies indicating that personality would serve as an explanatory construct accounting for the developmental pathway to successful aging.