This article argues that C.S. Lewis is a highly relevant but largely neglected character educator for 21st century schools characterized by diversity. We make the case for the objective reality of Lewis's Tao, the moral law recognized in the moral precepts of a wide range of cultures and traditions. We show why these universal precepts are foundational for character education, whether in the school or home, that help young people understand what is truly good and right and live accordingly. The article describes the Narnian Virtues character education research project, which tested a curriculum based upon 3 novels in Lewis's "Chronicles of Narnia" and was implemented over a 6-week period with 160, 9-14 year-old students in 5 socially and ethnically diverse United Kingdom schools. We report our findings, consider implications, and make recommendations for further research, most notably for increasing parents' engagement with the Narnian Virtues project and their children's character education.