In this study, we examined the potential influence of childhood and adult socioeconomic status (SES) on probable depression, suicide ideation, and self-esteem among men (N = 2938) and women (N = 4319) aged 50 years and older in South Korea. Our data came from the 2018 Korea Welfare Panel Study. Probable depression was defined as a score ≥16 on the modified Center for Epidemiologic Studies Depression Scale. We assessed suicide ideation with a single item. We assessed self-esteem with the Korean version of the Rosenberg Self-Esteem Scale. The results of multiple regression analyses showed that childhood economic status was rarely associated with mental health. However, current income consistently was associated with all outcomes in both sexes. Unemployment also had important health implications, especially for suicide ideation in men. Notably, the potential influence of income and employment status appeared to outweigh that of education, but not for self-esteem. Childhood economic status, but not adult SES, may have little implication for late-life mental health in present-day South Korea, which has gone through dramatic social and economic changes over the last half century. We discuss the socioeconomic implications of these findings.