Aim <p>This study was aimed to examine the relationship among witnessing workplace bullying, resilience, and professional identity in student nurses, and to investigate the mediating and moderating effects of resilience on the relationship between witnessing workplace bullying and professional identity.</p> Background <p>Workplace bullying is an increasingly serious problem in nursing practice and can affect the professional identity of student nurses. Resilience, a potential protective role, must be examined in relation to witnessing workplace bullying and professional identity.</p> Method <p>Cross-sectional design and secondary data analysis were conducted. 127 junior and senior nursing students in eight colleges and universities were recruited.</p> Results <p>A significant positive correlation was found between resilience and professional identity (<i>r</i> = 0.51, <i>p</i> &lt; 0.001). However, the mediating and moderating effects of resilience were not significant.</p> Conclusion <p>Resilience is a crucial factor in promoting professional identity among nursing students. However, further research investigating witnessing workplace bullying, resilience, and professional identity is required.</p>