Recent studies have indicated that early childhood education (ECE) teachers' responsibilities have expanded to include leadership functions. In school contexts the phenomenon is called teacher leadership and the same concept has recently been adopted in ECE research literature. Additionally, there are other concepts and perspectives connected to leadership performed by ECE teachers. This literature review aimed to explore the conceptualization, characteristics, and enactment of leadership performed by ECE teachers. Leadership that ECE teachers perform in their work is characterized as a multidimensional and contextual phenomenon, and as intentional influencing, which is based on collaboration and distribution. The focus is on pedagogical leadership, although teacher leadership is a broader concept, which can also include administrative tasks. The findings of the review suggest investigating teacher leadership more within the distributed leadership perspective by focusing on ECE teachers' essential role in enhancing other actors' participation in leadership. The literature review reflects the need to clarify the conceptualization of ECE teacher leadership for developing teacher leadership research, especially in an ECE context.