Introduction:The coronavirus disease -19 (COVID-19) brought a huge impact on all aspects of humankind. Adolescence plays a significant role in a persons development. Being at this stage during the pandemic had several challenges, such as developing mental illnesses like depression, anxiety, and stress. Objectives:This study aimed to evaluate the psychological impact of the COVID-19 pandemic on adolescents, including depression, anxiety, and stress. Methods: This descriptive cross-sectional study was conducted on eligible adolescents following in the primary health care (PHC) centers of National Guard Health Affairs, Jeddah, Kingdom of Saudi Arabia. It included adolescents aged 10 to 24 years old. Excluded in this study are those that have known psychiatric illness, mental retardation, and developmental disease. Results: Depression was found to be significantly correlated to location, smoking, and having a family member diagnosed with mental illness at p-values of 0.024, 0.033, and 0.040, respectively. Anxiety was significantly correlated as well with location and friends diagnosed with mental illness at p-values of 0.045 and 0.024, respectively. The correlation between stress and the city where the patient lived, friends diagnosed with mental illness, and smoking were significant at p-values of 0.010, <0.001, and 0.003, respectively. Conclusion: Prolonged lockdowns and restrictions brought about by the pandemic have caused negative impacts on adolescents. Thus, these post-pandemic effects must be addressed to provide appropriate actions by healthcare organizations and the government.