The aim of this study is to investigate the phenomenon of spiritual leadership manifested in Indonesian Muslim culture; a culture that is underrepresented in literature. In this study, spirituality was conceptualized as religious spirituality. By using qualitative research and within the exploratory multiple-case study, three Indonesian Muslim business leaders and 29 employees were interviewed. In addition to semi-structured interviews as the main data collection techniques, reviews of documentary materials were used where appropriate to triangulate the findings. Template Analysis was used to produce themes reflecting participants' perception of spirituality and spiritual leadership. The research findings suggest that Fry's Spiritual Leadership Theory is generally applicable to Indonesian Muslim culture. It also confirms that in this context, it is more relevant to define spirituality as religious spirituality. For Muslims, Islam is not only connoting the rituals and religious institutions but a complete way of life. Furthermore, inner life is an essential element in shaping Muslim leaders to become a spiritual leader. In this respect, this study confirms that the leadership behaviour of Indonesian Muslim business leaders is derived from Islamic religious or spiritual practices that positively influence development of hope/faith in a transcendent vision of service to key stakeholders and the values of altruistic love, which in turn resulted in spiritual well-being of leaders and their followers. The research contributes to the related literature by providing examples of the application of spiritual leadership theory in Indonesian Muslim culture. In addition, by providing an understanding of spirituality within religion-based conception of spirituality, this study enhances knowledge of spiritual leadership model, especially Fry's Spiritual Leadership Theory. The contribution of this study also lies in the exploration of the meaning of spirituality thoroughly as well as by revealing new aspects of spiritual leadership that has not been revealed in previous studies on spiritual leadership, such as sincerity and the leader as a role model.