In the ever-changing 21st-century landscape characterised by emerging global and technical trends, the search for relevant leaders in school systems relies on the premises of building a conducive, adaptive and inclusive learning environment. Thus, this article aims to examine the mediating effect of transformational leadership attributes of school leaders on their cultural intelligence and the organisational health of secondary schools in Kuala Lumpur. Using a quantitative design, a survey questionnaire was administered to 476 school leaders in Kuala Lumpur. The results from the survey were analysed using PLS-SEM technique with SmartPLS software, which established the direct effects of cultural intelligence on transformational leadership and organisational health. In addition, transformational leadership was determined to have a direct effect on organisational health. The evaluation of the structural model revealed that transformational leadership has a mediating effect on cultural intelligence of school leaders and organisational health of secondary schools. Aside from advancing the theoretical understanding of school leadership, the results of this article present reflection points for current and aspiring school leaders, opportunities for inclusion of cultural understanding in school leadership programs, and provisions in policies in organisational development in multicultural schools.