Objectives <p>This study aimed to examine the association between gratitude and defending behavior in response to school bullying among Chinese early adolescents and to evaluate the effects of three types of interventions (i.e., gratitude curriculum, gratitude journal, and gratitude visits) on gratitude and defending behavior.</p> Methods <p>Two studies were conducted. Study 1 employed a cross-sectional survey involving 912 seventh- and eighth-grade students from two schools (52.41% girls, 53.62% seventh-grade students, 12–18-year-olds). Study 2 involved the development of a gratitude curriculum and employed a four-armed randomized controlled trial with 16 classes, in which adolescents were randomly assigned to a gratitude curriculum intervention, a gratitude journal intervention, a gratitude visit intervention, or a control condition.</p> Results <p>The results indicated that gratitude was positively associated with defending behavior in school bullying. In addition, both the gratitude curriculum and the gratitude journal significantly increased adolescents’ gratitude from pre- to postintervention and resulted in higher postintervention levels than the control group, whereas gratitude visits did not significantly enhance gratitude. Similarly, the gratitude curriculum and the gratitude journal significantly improved defending behavior both from pre- to postintervention and relative to the control group, whereas gratitude visits led to significant improvements in defending behavior only from pre- to postintervention. Furthermore, no significant postintervention differences in gratitude or defending behavior were observed among the three intervention groups.</p> Conclusions <p>This study provides evidence that gratitude is associated with defending behavior in school bullying contexts, highlighting its potential relevance for school-based anti-bullying interventions.</p>