Young adults the year after high school experience changes in lifestyle and circumstances and tend to experience more oversleeping. However, there are few studies on oversleeping in young adults. This study aims to identify the sociodemographic factors related to oversleeping among young adults in Korea using nationally representative data. This study analyzed self-reported and cross-sectional data in 2016 from a sample of 1876 participants from the Korean Children and Youth Panel Survey, which included respondents one year after high school graduation. Oversleeping was defined as sleeping 9 or more hours a day on average. Logistic regression models were analyzed to test a multivariate association between independent sociodemographic variables and oversleeping. Over one-tenth of young adults reported oversleeping. Oversleeping was associated with household income (OR = 0.99, p = 0.011) and smoking (OR = 1.52, p = 0.041). In addition, when compared to non-working college students, college students who were working (OR = 2.58, p = 0.021), non-students who were working (OR = 1.68, p = 0.048), and non-students who were not working (OR = 3.07, p < 0.001) were more likely to report oversleeping. Oversleeping among young adults was associated with major sociodemographic factors including household income (−), smoking (+), and academic and working status (+). These findings suggest the significant role of sociodemographic factors as predictors of oversleeping and emphasize the importance of examining various factors to achieve a better understanding of oversleeping in young adults.
