Leadership may play a key role in improving educational processes and, potentially, in enhancing student academic achievement. However, this apparently simple claim conceals a complex reality, as there are many leadership models and a wide range of school leader characteristics that may bear an impact on their effectiveness. In fact, even the very definition of school leader is contentious. Therefore, determining the impact of the role played by school leaders on student academic achievement poses a challenge. In this review, we present the state of play as regards the literature that forges a link between leadership, types of leadership and leader characteristics with academic achievement.