Workplace bullying among nurses is a prevalent and serious problem in health care settings around the world with detrimental physical, psychological, and organizational consequences. Nursing students and novice nurses are more likely to encounter incidents of workplace bullying in their clinical settings. Although workplace bullying is one of the biggest challenges that the nursing profession faces today, there is a scarceness of interventional research aimed at educating nursing students on effective responses to workplace bullying. Thus, the primary aim of this study was to evaluate the effectiveness of an online educational tool in enhancing knowledge about workplace bullying and in improving self-efficacy and intent to intervene related to workplace bullying among undergraduate nursing students in two Canadian schools of nursing. The study design was quasi-experimental, using a one group pre-test/post-test. Forty-one undergraduate nursing students participated. Recruitment ceased with the onset of the COVID-19 pandemic. Participants completed a demographic questionnaire, a 20-item, self-developed Workplace Bullying Knowledge Assessment tool and the Self-Efficacy to Respond to Disruptive Behaviours (SERDB) scale with an additional item about intent to intervene. Results relative to the effectiveness of the intervention to enhance participants' knowledge, self-efficacy, and intent to intervene are presented from the paired samples t-test and Wilcoxon-Signed Rank test of pre- and post-intervention differences. Additionally, a regression analysis tested for interaction effects of independent participants' variables. Although the educational intervention enhanced nursing students' knowledge about workplace bullying, self-efficacy, and intent to intervene, caution is needed in the interpretation of the statistically significant results due to the small sample size. This study highlighted the importance of including evidence-based educational tools about workplace bullying in nursing curricula. This study adds a substantive contribution to current nursing knowledge by developing and evaluating evidence-based online modules to prepare nursing students in the identification and management of workplace bullying in healthcare settings. Evaluating the effectiveness of the online educational tool was important in discerning its future applicability in undergraduate nursing curricula. Recommendations for future research include further development and testing of the Workplace Bullying Knowledge Assessment tool as well as a longitudinal study to determine outcomes.