Objective - The present study aimed to obtain a comprehensive view of the up-to-date global evidence on the impact of the COVID-19 pandemic on adolescent mental health and well-being.Background - A great deal of concern has been raised about the negative impact of the current health crisis on adolescents.Methods - Electronic literature searches were conducted in July 2022 in the Google Scholar database. A total of 57 original research articles and review articles that met the criteria were selected and reviewed. They comprised studies with adolescent populations from more than 20 countries across 5 continents.Discussion - The impact of the COVID-19 pandemic on adolescent mental health was identified as negative, positive, and fluctuating over the course of the pandemic. The accumulated evidence supports the assertion that there has been a considerable and wide-ranging negative impact. However, the long-term and short-term effects differ. Some positive effects of the current pandemic have also been reported: a small number of adolescents seemed to thrive overall, and the majority of them even seemed to have experienced positive changes in some specific aspects. Even so, the positive impact can hardly outweigh the negative. The fluctuating trajectories of adolescent mental health during the pandemic could be attributed to infection rates, quarantine, the severity of containment measures, the accumulation of stressors, etc.Conclusion - There is evidence for both negative and positive impacts of the COVID-19 pandemic on adolescent mental health and well-being. Further research is needed to study the complex impact of a health crisis of such magnitude.