Self-rated health (SRH) is a robust indicator of mortality, morbidity, and health behaviors. Despite consisting of a single item, SRH is a comprehensive measure that captures overall health status and encompasses biological, social, and psychological factors that influence health. Predictors of SRH across these domains are not well understood, particularly among young healthy individuals. Using a biopsychosocial approach, this dissertation explored in three separate studies biological markers of systems implicated in stress physiology (i.e., immune, autonomic, and endocrine), social determinants of health, and psychological factors that are relevant to SRH. Study 1 (N = 99) showed that higher levels of salivary (p = .011) and serum (p = .013) inflammatory markers predicted higher odds of reporting poor SRH, highlighting that inflammation is associated with worse SRH. Study 2 (N = 148) explored whether cardiovascular reactivity to stress, indexing activity of the sympathetic nervous system, and discrimination, a social determinant of health, were related to SRH. The study showed that increases in pre-ejection period (PEP) reactivity were associated with a 2% greater chance of reporting better SRH. Findings for the association between discrimination and SRH differed based on the participants’ ethnicity. Study 3 (N = 50) investigated endocrine markers in relation to SRH and documented that higher levels of placental corticotropin releasing hormone (pCRH) were associated with increased odds of poor SRH (p = .046) among a sample of pregnant Latinas. Everyday discrimination (p = .005), familism (p = .021) and positive trait emotion (p = .003) predicted lower odds of poor SRH. Findings from this dissertation provide direction for further examining SRH through a biopsychosocial lens. Implications for understanding the utility of SRH as a screening tool to identify individuals at risk for poor health outcomes are discussed.