BackgroundThe crucial differences in longevity related to quality of life and specific traits in the oldest old need to be investigated from a socioecological perspective because their impacts may differ in the oldest-old adults. This entailed estimating the impacts of quality of life and personal traits on the longevity of the oldest old in South Korea from a socioecological perspective. MethodsThe data were obtained from interviews with 170 South Koreans aged 95 to 108 from June 2017 to February 2020. Specifically, we interviewed 130 residents aged 100 to 108 and 40 aged 95 to 99 across 36 provinces in South Korea. This study incorporated an analytical model to observe the effects that were distributed across individuals, societies, and countries from a socioecological perspective. The factor analyses of the interview responses revealed significant correlations and hierarchical models.ResultsSeven factors were identified as major to quality of life and traits, and five in particular, industriousness, physical labour, weight 60kg, friends, meat intake, affected their longevity. In addition, fewer feelings of depression or anxiety and higher life satisfaction and living standards also influenced the longevity. ConclusionsThe quality of life and traits of South Korea’s oldest old appear to have a decisive latent impact on longevity factors. We identified seven crucial determinants of longevity in the oldest old: industriousness, labour, weight, friends, and meat intake, fewer feelings of depression or anxiety, and higher life satisfaction. Thus, those who seek longevity might emulate these traits of the oldest old.