Limited studies have investigated the relationship between subjective well-being (SWB) and longevity among older adults. Additionally, no existing research has explored racial/ethnic differences between SWB and longevity in the U.S. Guided by the Main Effect Model, the Stress-Buffering Model, and the Stratification Theory, this study aimed to determine the impact of SWB on longevity. Furthermore, I sought to determine which component(s) of SWB, whether positive affect, negative affect, and/or cognitive evaluation, independently predicted longevity. Lastly, the interaction effect of race/ethnicity and SWB on longevity was assessed. Using the Kaplan-Meier Estimator and the Cox Proportional Hazards (PH) Model, I found that SWB was predictive of longevity among older adults. A higher level of SWB was associated with a lower mortality risk. More importantly, a one-point increase in SWB was associated with a 3% lower mortality risk after adjusting for demographic factors (age, gender, and race/ethnicity), socioeconomic status (SES) covariates (income, education attainment, marital status, and number of health insurances), physical health (number of physical health conditions and self-rated health), and mental health status (depression and anxiety). In addition, positive affect was associated with mortality risk after adjusting for demographic and SES factors, and cognitive evaluation was a significant predictor of longevity after adjusting for all covariates. However, negative affect was not associated with mortality risk. Lastly, the interaction between SWB and race/ethnicity did not predict longevity. These findings highlighted the importance of SWB for longevity among older adults in the U.S. Suggestions for future research and implication for public policy and clinical intervention are discussed.