Although a body of research has targeted predictors of well-being and depression in old age, the consideration of oral health-related quality of life (OHRQoL) as a predictor of these major psychosocial endpoints has been rare in the previous literature. The objective of this study was to test whether OHRQoL is associated with well-being and depression, after controlling for relevant confounders; also, the mediating role of subjective health, a major predictor of both well-being and depression, has been explored. OHRQoL was measured by two commonly used assessment instruments, the geriatric oral health assessment index (GOHAI) and oral health impact profile (OHIP); well-being was assessed by the Philadelphia Geriatric Center Morale Scale (PGCMS) and depression by the self-rating depression scale (SDS). We used a subsample of 197 participants from the older cohort (1930-1932) of the Interdisciplinary Longitudinal Study of Adult Development. Regression models and structural equations modeling (SEM) were used for the test for study variable relationships. Both GOHAI and OHIP revealed significant associations to both PGCMS and SDS at the bivariate level. In regression analyses considering gender, household situation, subjective health, and both OHRQoL indicators, only OHIP remained a significant predictor of well-being and depression. In addition, supportive evidence for a mediating role of subjective health regarding the linkage between OHRQoL and an overall latent construct of well-being was found in the SEM analysis. In conclusion, OHRQoL is significantly linked with well-being and depression in old age, while subjective health is able to mediate the relationship. The generally underrated role of OHRQoL with respect to well-being and depression in late adulthood deserves more attention.