Background: The current coronavirus disease 2019 (COVID-19) is a public health emergency and universal hazard. Governments have ordered all people to spend all their time at home and imposed school closures as an emergency measure. In such situations, physical and mental health problems are significant concerns. Aim: This study aimed to evaluate leisure time, physical activity, and psychological well-being among adolescents during COVID-19. Study design: A cross-sectional research design. Setting: The study was conducted in Dakahalia Governorate, Egypt. Sample: The study involved a convenience sample of 1200 adolescents through a validated self-administered online questionnaire. Tools: It included four parts; Part I: Characteristics of studied adolescents, Part II: leisure time questionnaire, Part III: Physical activity questionnaire, and Part IV: Psychological well-being scale. Results: 55.0% of the studied adolescents reported that relaxing activities were the type of activity that was practiced more habitually during leisure time. 59.80% of the studied adolescents had low physical activity. 64.9% of the studied adolescents had moderate psychological well-being. There was a statistically significant positive correlation between practicing the practical sport in leisure time and satisfaction with leisure time, physical activity, and psychological well-being among adolescents during COVID-19. Conclusion: The results from this study concluded that the studied adolescents do low physical activity without any satisfaction about leisure time which is reflected in their psychological well-being during COVID-19. Recommendations: Future research should replicate these analyses in a non-pandemic situation. It must focus on testing the longitudinal associations reported here in non-pandemic circumstances.