The current COVID-19 (SARS-CoV-2) pandemic has generated negative psychological effects on the global population. In this context, one of the most vulnerable groups is adolescents, who have faced a range of challenging scenarios. The consequences of this pandemic for the wellbeing of adolescents need to be researched across countries. From this perspective, this study aims to characterize the wellbeing of adolescents from Mexico and Chile during the pandemic and delve into the relationship between victimization and the hedonic and eudaimonic types of wellbeing. Data from adolescent students (n = 3,275) were used, with the support of the Global Research Alliance. Descriptive and regression analyses were conducted and their results indicated that: 1) Late adolescents scored lower on flourishing, and males scored higher than females. There was also a higher prevalence of languishing in late adolescents from both countries, as well as high levels of languishing in non-binary adolescents, especially in Chile; 2) There was a high prevalence of poly-victimization, with the highest percentage reported by females and the late adolescent group in both countries; 3) Non-victims had a higher probability of being in the flourishing group than victims in both countries; 4) Poly-victimization especially had an effect on the eudaimonic wellbeing of early adolescents and on the hedonic and eudaimonic wellbeing of late adolescents in both countries. Implications related to the mental health policies for adolescence are discussed in terms of how to increase adolescent wellbeing.