Contrary to guidance counsellors elsewhere in North America who hold a master's degree, career and guidance counselling services in secondary schools in Ontario are delivered by teachers who have completed additional undergraduate studies. Guidance counsellors are pivotal components of the school as they complete tasks that promote students' overall development. The aim of this qualitative study was to explore how teachers perceive and describe the process of becoming guidance counsellors in Ontario. The thematic analysis revealed four major themes that articulated the process of becoming a guidance counsellor in Ontario: peer guidance, contextual factors, professional experience, and theoretical knowledge.