This paper investigates the case of Singapore where there are teachers' unions but industrial actions are rare. It questions why and how has educator organising, steered by Singapore Teachers' Union, transformed? Our findings show that historical, political, and socio-economic dynamics have influenced the transformation of STU. For more than seventy years, STU has been a champion, supporter, and advocate of teachers in Singapore through industrial, professional, and social unionism. We argue that the legacy of STU's struggles, throughout its contentious relationship with the colonial government and collaborative rapport with the local government, has laid the foundation that enables the development of teachers and the high quality of education that the country is currently known for globally. However, persisting residual issues surrounding teachers' wellbeing due to the high expectations of teachers and teaching call for a review of this state-labour relationship.