Underpinned by the transactional model of stress (Lazarus and Folkman in Stress, appraisal, and coping, Springer, Berlin, 1984), the aim of this pre-registered study was to test the role of cognitive appraisals (threat, challenge, control, blame, and perceived social support) in the longitudinal relationship between peer-victimization and depressive symptomatology. Measures of peer-victimization, cognitive appraisal (threat, challenge, control, blame, and perceived social support), and depressive symptomatology were included in a self-report questionnaire, and data were collected at three-time points each one month apart. Participants were 530 adolescents aged 11-14 who reported experiencing peer-victimization at the beginning of this study. Results of the cross-lagged panel analyses found both an association between peer-victimization and depressive symptomatology after three months, alongside an association between depressive symptomatology and later peer-victimization. Perceived social support from parents/guardians, teachers, or close friends did not significantly moderate this relationship. Peer-victimization at the start of the study was significantly associated with challenge, but not threat, appraisals one month later. Both threat and challenge appraisals in the second month of the study were related to depressive symptomatology at the end of the study, one month later. A small significant total indirect effect via threat and challenge appraisal was found, though neither was a significant mediator on its own. This study highlights the role of challenge and threat appraisals in adolescents' adaptation to peer-victimization.