This paper investigates whether adolescents’ core self-evaluation (CSE), a broad personality construct capturing individuals’ appraisal of their self-worth and capabilities, predicts interpersonal trust decades later. Using nationally representative longitudinal data from the 1970 British Cohort Study, we construct CSE measures from self-esteem, locus of control, and emotional stability at age 16 and examine their relationship with trust reported at ages 34, 42, 46, and 50. We find that higher adolescent CSE is consistently and positively associated with greater trust in others later in life. Each component of CSE independently predicts trust, and the composite index shows robust associations even after controlling for demographic background, cognitive skills, and early mental health. The estimated associations are comparable in magnitude to those between trust and cognitive ability. They are stable over time and are not explained by selection to the sample, educational attainment, labor market success, or family formation. Importantly, we find that the relative importance of CSE components varies by adolescent mental health: locus of control is more predictive among individuals with better mental health, while emotional stability plays a stronger role among those with elevated depressive symptoms. These findings underscore the long-term social relevance of core self-evaluation and highlight its importance as a psychological antecedent of trust.