Traditional bullying and cyberbullying are linked to adverse mental health outcomes. Student connectedness has been recently identified as a potential protective factor in these relationships. Nonetheless, the multilevel nature of these interactions has been frequently overlooked. The present study pretends to fill this gap by exploring the associations between individual levels of bullying and cyberbullying and three adjustment outcomes (i.e., suicidal behavior, symptoms of depression, and self-esteem), as well as the moderating role of the school level of student connectedness on these relationships. The participants in this work were 1,774 students aged 14-18 years (M = 15.70, SD = 1.26), of which 53.7% were female, from 31 secondary schools in Spain. We used previously validated self-reported questionnaires in this study. Traditional victimization and cybervictimization, as well as cyberbullying, were positively related to suicidal behavior and depression, and were negatively related to self-esteem. Conversely, individual levels of student connectedness were associated with lower levels of suicidal behavior and depression, and with higher levels of self-esteem. Moreover, school levels of student connectedness buffered the adjustment problems experienced by victims of cyberbullying. These findings highlight the importance of student connectedness as a possible target for school-based cyberbullying prevention.