Given discourse across the globe on school reform and the importance of teachers' work to school improvement, teacher leadership represents an opportunity to re-imagine school cultures, and to consider a range of factors that impact the teaching profession and contribute to overall school improvement. Based on a qualitative inquiry of 24 teacher leaders across two country contexts (Jamaica and the United States) and using the metaphor of 'awakening the sleeping giant', we argue that teacher leadership is an untapped phenomenon and a necessity for 21st century school improvement. Within this paper we draw on the teacher leaders' stories to provide an understanding of the power and resources residing in the domain of teachers' work. Through the findings we showcase that there are elements of teacher leadership that transcend specific school and country contexts based on school structure and historical precedents. The findings presented in this paper also highlight that teachers' work is highly political and that historical precedents related to power and gender created differences in how teacher leadership has been perceived and enacted. The paper closes with a discussion about the cross-cultural 'truths'' that emerged and the implications for teachers' work and school improvement.