Research regarding the practice of leaders' mindfulness has increased over the past several years. Emphasis on principals' mindfulness practices helped educational leaders become stronger during these uncertain and stressful times. Specifically, researching how principals use mindfulness in a school setting advances educational leadership by exploring this relationship. This systematic review aimed to understand how principals use mindful practices in their schools and relationships with their stakeholders. Attributes of mindfulness used in their leadership practices were explored to influence ways to enhance educational leadership training. Fourteen peer-reviewed research studies from 2010-2021 were reviewed. There were five key themes identified related to a principal's use of mindfulness: (1) school organization; (2) decision-making; (3) well-being; (4) leadership attributes; and (5) student success. This article concluded by discussing the key findings and suggestions to guide future research on principals' mindfulness.