The Singapore education system had gone through several pivotal changes since our independence in 1956 in order to meet the societal needs of the nation and to stay relevant with times. The focus of education progressed from developing foundational knowledge of literacy and numeracy skills towards instilling values and attributes in each child. Results from the internationally benchmarked tests in 2015, the Programme for International Student Assessment (PISA) and the Trends in International Mathematics and Science Study (TIMMS), have shown that the high performance of Singapore students is largely due to the country’s teachers and their roles in the system. However, as the world move towards the twenty-first century, the roles and responsibilities of teachers will have to change. The purpose of this chapter is to discuss the changing roles of the teacher in the twenty-first century and how teacher education and professional development in Singapore has changed in tandem in order to ensure that the teacher is adequately prepared and supported to meet the challenges of twenty-first-century classrooms and schools. Innovations in policy and practice will be highlighted and the strong systemic coherence that helps ensure that research-informed policies are implemented with fidelity will be showcased.