Objectives: The understanding of how subjective socioeconomic status (SSS) relates to objective socioeconomic status (OSS), and how both conditions act together in oral health outcomes is still unclear. This study aims to test the independent and joint association between OSS and SSS with oral health, to assess the role of socioeconomic status discrepancies, and to evaluate the role of SSS in the association between OSS and oral health. Methods: Data from 1140 adults from a population-based study in Southern Brazil were used. We applied diagonal reference models DRM to disentangle the effects of OSS (education) and SSS (MacArthur Scale) to oral health outcomes. The outcomes were functional dentition clinically evaluated (FD ≥20 teeth) and self-reported oral health SROH. We also examined the discrepancy between OSS and SSS to oral health indicators and the effect measure modification (EMM) of SSS on the association between OSS and oral health. Results: Subjective socioeconomic status and OSS contributed equally to SROH, while OSS explained a substantially higher amount of FD than SSS (0.85 vs 0.15). An EMM of SSS was found on the association between OSS and fair/poor SROH, with a relative excess risk due to interaction (RERI) of 1.08. Less evidence of EMM was found for FD (RERI = 0.14). Individuals with lower SSS and OSS had four times the risk of the outcomes than the reference group. Conclusions: Adults with concordant lower SSS and OSS have a worse oral health than those with concordant higher status. There was evidence that the association between OSS and SROH is modified by SSS.