This article provides the practical and theoretical justifications for the growth of teacher leadership, in the Singapore education context. It argues that since 2001, the importance of teacher leadership has been growing, and more significantly in the last five years, which is due to several factors. First, the race towards attaining 21st century competencies in students, yet maintaining academic rigour in terms of outcomes. Second, the growing complexity of education contexts. These conditions had caused schools to invest their resources in strengthening classroom instruction through building teacher capacity and competency, and the leadership that support it. However, for the latter, what is becoming evident in schools and education systems is the distribution of instructional leadership. This article provides the practical and theoretical discussions on the growing importance of teacher leadership using the Singapore education context as an illustrative case, and discusses implications for school leaders.