Background: The majority of studies on the role of psychological resources linking childhood socioeconomic status (SES) and adult health have been conducted in Western countries. Empirical evidence for mediation effects of psychological resources is currently lacking in Japan. Purpose: The purpose of this study was to investigate the mediating effect of psychological resources (mastery and sense of coherence [SOC]) on the association between childhood SES and current health. Method: Analyses were conducted on cross-sectional data (1,497 men and 1,764 women) from the Japanese Study of Stratification, Health, Income, and Neighborhood Study (J-SHINE) in Tokyo. Psychological resources (mastery and SOC), childhood SES (parents’ education and perceived childhood SES), and current health of adults (psychological distress measured by K6 and self-rated health) were measured using a self-report questionnaire. Results: Mastery and SOC significantly and independently mediated the association between childhood SES and current health in the total sample after adjusting for age, gender, and respondent education, regardless of type of SES or health outcome indicators. Similar mediation effects were observed for both men and women. A few gender differences were observed; specifically, SOC significantly mediated the association between parents’ education and current health only among women, and it mediated the association between perceived childhood SES and current health only among men. Conclusions: Overall, the findings underscore the importance of the mediating role of psychological resources in the association between childhood SES and current health.