ObjectiveTo examine associations between television (TV) viewing, reading, physical activity (PA), and psychosocial well-being among a representative sample of young South Korean children aged 0-5years. MethodsFindings are based on 1,774 children who participated in the Korea Children and Youth Survey. All measures were questionnaire-derived. Psychosocial well-being included social, interactive, and emotional skills (=.7-.9), and the top quartile denoted high psychosocial well-being. Multiple logistic regressions were performed to examine relationships after controlling for several confounders. ResultsCompared to children who participated in PA for <1hr/week, those who participated in PA for 1-<3hr/week were more likely to show high emotional skills (odds ratio [OR]: 1.40, 95% confidence interval [CI] [1.02, 1.93]), and those who participated 3hr/week were more likely to show high social (OR: 2.01, 95% CI [1.45, 2.78]) and interactive skills (OR: 1.39, 95% CI [1.01, 1.92]). During weekdays, children who read 1-<3hr/day and 3hr/day, compared to <1hr/day, were more likely to show high social (OR: 1.61, 95% CI [1.20, 2.16] and OR: 2.47, 95% CI [1.31, 4.67]) and emotional skills (OR: 1.57, 95% CI [1.16, 2.13] and OR: 2.58, 95% CI [1.34, 4.98]). In addition, children who read 1-<3hr/day, compared to <1hr/day, were more likely to show high interactive skills (OR: 1.44, 95% CI [1.08, 1.92]). Similar findings for reading on weekends were observed. TV viewing was not associated with social skills or interactive skills. TV viewing for 1-<3hr/day, compared to <1hr/day, was associated with increased odds of high emotional skills (OR: 1.71, 95% CI [1.28, 2.27] on weekdays; OR: 1.90, 95% CI [1.39, 2.61] on weekends). ConclusionPA and reading primarily showed favourable associations with psychosocial well-being, whereas TV viewing did not; thus, PA or reading may be a better option over TV viewing for optimal psychosocial well-being among young South Korean children. These findings should be confirmed with stronger study designs.