Objectives: This study was performed to identify factors associated with self-perceived depression among Korean adolescents during the coronavirus disease-2019 (COVID-19) pandemic. Methods: A total of 1,710 middle and high school students (54.7% boys, 45.3% girls) participated in a cross-sectional survey. The self-administered questionnaire included items assessing the changes in perceived depression and daily life patterns during the COVID-19 pandemic. Other questionnaires included sociodemographic data, three item version of the UCLA Loneliness Scale, Gratitude Questionnaire-6, and Big Five Inventory-10. Multivariable logistic regression was used to examine the factors associated with increased perceived depression during COVID-19 pandemic. Results: The prevalence rate of perceived depression was 18.4%. The multivariate logistic regression analysis revealed that high loneliness, neuroticism, decreased social relationships, increased familial conflict, increased internet using time, irregular meal pattern, and high perceived academic stress were significantly associated with perceived depression. Conclusions: Our findings suggest that interventions aimed at coping with stress and regulate perceived depression due to sudden life style changes are necessary for adolescents, as ...