Through a quantitative approach, this study implemented Angelle and DeHart's Teacher Leadership Inventory (TLI) analysis (2011) with the aims of exploring the nature of teacher leadership in International Islamic schools and understanding the variables that affect teacher leadership from teachers' perspectives. A one-way ANOVA was used to determine whether there were any statistically significant differences between the means of two or more independent and unrelated groups, and it was conducted for each variable (i.e., school level, degree level, gender, years of experience, and status for leadership position) and the four factors of the TLI. The findings revealed that gender, leadership position, and nationality affected the teachers' perspectives regarding teacher leadership in Islamic schools. We argue that these differences should be taken into consideration by Islamic school leadership and policy makers when establishing schools and building systems, thereby avoiding assumptions that teacher leadership is embedded within their systems in all countries (Muslim and non-Muslim).