This study analyzes the influence of authentic leadership—which has emerged as the most prominent topic in recent leadership research—on team effectiveness. Research on authentic leadership criticizes the limitations of existing leadership approaches that influence performance through exercising authority over tasks and subordinates, and argues that leaders who are honest with themselves, rather than with others, can make greater contributions to a team's short- and long-term performance. That is, authentic leaders are those who recognize themselves based on an understanding of who they are by identifying their own strengths and weaknesses, and who strive to reduce the gap between their ideal self and actual self through self-regulation. Proponents argue that this is a clearly distinct and independent concept from other leadership styles. Accordingly, this study simultaneously analyzed the influence of transformational leadership—representing existing leadership approaches—and authentic leadership, and examined and compared their differential effects on task-related effectiveness (team performance and team creativity) and effectiveness related to maintaining organizational order (organizational commitment and perceptions of organizational politics). The results showed that transformational leadership had a positive effect on team performance and team creativity but did not have a significant effect on organizational commitment and perceptions of organizational politics. In contrast, authentic leadership was found to have a statistically significant effect not only on performance-related effectiveness such as team performance and team creativity, but also on order-maintenance-related effectiveness. Based on these research findings, the implications of transformational leadership and authentic leadership for organizations and teams, as well as their implications for managers, were discussed in depth.