Oldest-old women are known to live at the intersection of multiple socioeconomic disadvantages in South Korean society. This study classified oldest-old Korean women into several socioeconomically homogeneous classes based on various socioeconomic status (SES) risks and compared health characteristics among the identified classes. This cross-sectional study utilized the 2019 Korean Community Health Survey, including data from 11,053 women (≥80 years). Latent class analysis determined the number of underlying socioeconomic classes based on nine selected SES variables. Four distinct socioeconomic classes were identified: “Urban, living alone, recipient of NBLSS, moderate education, leisure activity” (Class 1), “Rural, traditional house, living with others, not financially deprived, low education, employed” (Class 2), “Urban, living with family, financially affluent, not employed, no barriers to healthcare” (Class 3), “Rural, traditional house, living alone, financially deprived, uneducated, employed, barriers to healthcare” (Class 4). Depressive symptoms, subjective stress, and the prevalence of sleep disorder and diabetes were higher in Class 1 compared to other classes. Health-related quality of life, perceived health, and self-rated oral health were the poorest in Class 4. Class 3 reported the best health status. Understanding the intersecting SES risk factors in this group can aid in developing targeted interventions.