The purpose of this study is to reveal leadership roles of school principals having impact on school mindfulness. This quantitative study with correlational design involves 389 teachers from secondary and high schools in Buyukcekmece, Istanbul province. The researchers used the 'School Mindfulness' and 'Leadership Roles of School Principals' scales. In the study descriptive statistics, correlation and regression analyses were used to reveal the prediction level. The findings showed that visionary and transformational leadership roles of school principals strengthen school mindfulness and the sub-categories of faculty and school principal mindfulness. In addition, instructional leadership roles of school principals predict principal mindfulness. However, cultural leadership was found to have no effect on school mindfulness.