This article focuses on ancient Daoist wisdom, together with its associated principle of "yin-yang," and their contemporary significance in terms of how they might be applied within today's classrooms as foundations for a harmonious world. It does so by illustrating the significance of Daoism and "yin-yang" from both historical and philosophical perspectives, as well as highlighting their spread to the West in relatively recent years in which growing numbers of classroom teachers are applying Daoist wisdom in their classrooms. It then suggests further approaches through which teachers might continue applying Daoist wisdom towards a harmonious "yin-yang" balance based on the associated Daoist principles of the virtue-less virtue of "de" and the naturalness of "ziran," as well as the effortlessness of "wuwei" and the universal abundance of "qi" energy.