The role of pre-service teacher education is crucial in culturally diverse contexts where conflict exists. Thus, this study examined whether pre-service teachers' multicultural sensitivity can be increased through a Transformative Learning Theory-based online course. The developed course underwent expert evaluation and pilot-testing before its implementation. T-test comparisons of pre- and post-tests with 97 Filipino pre-service teachers show a statistically significant increase in overall multicultural sensitivity. While the effect size is modest based on Cohen's d, 84.5% of the pre-service teachers claimed to have experienced positive change. All pre-service teachers who claimed to have experienced positive change identified the individual reflection activities to have influenced their change. This study can be replicated in other contexts. The course design can be adopted, but some of the course content has to be contextualized. The findings of this study can inform both theory and practice on how multicultural sensitivity can be increased and how Transformative Learning Theory can be applied in online course design.