In this book, first of all, the concept of leadership is emphasized, the importance of leadership is emphasized, and classical and modern leadership approaches are briefly mentioned. Afterwards, the concept of team leadership is discussed after the concept of team, the characteristics that effective teams should have, why teams are needed and the factors that affect the success of the team. In this framework, functional leadership approach has been proposed as the most effective leadership style for team leadership. With the functional leadership approach, a model has been presented by explaining the situational conditions and processes that are effective in the emergence of successful teams.