Understanding Asian Americans' lives and challenges would be enhanced by examining group-specific contributors to subjective well-being (SWB). The components and predictors of SWB, as well as other dimensions of positive psychology, are understudied in mainstream psychological and Asian American literatures. The present study addressed this gap in the literature by (a) exploring multiple domains of SWB-hedonic, eudaimonic, social, physical, and financial well-being; (b) examining joint and distinct influences of Big 5 personality traits and outcome expectancies; and (c) considering experiences that foster life flourishing among Asian Americans. Asian American college freshmen (N = 456; 55.56% women; M-age = 17.95 years) completed self-report measures assessing their Big 5 personality tendencies, optimism and pessimism, and SWB. Confirmatory factor analytic findings supported the notion that SWB could be conceptualized as comprised of 5 distinct but related domains. Confirmatory factor analyses also indicated that optimism and pessimism were partially independent constructs. Structural equation models indicated that extraversion, conscientiousness, and agreeableness were stronger predictors for domains of SWB than optimism or pessimism. Optimism partially mediated the relationships between extraversion and eudaimonic well-being as well as between neuroticism and physical wellbeing. Pessimism did not mediate the personality-SWB linkage. Results highlight the predictive impact of personality traits on SWB. Findings also illuminate indirect pathways of these influences through optimistic expectancies for personality and SWB domains, but unexpectedly not through pessimistic expectancies. Cultural considerations underlying these patterns, limitations, and future directions are discussed.