Internationally, educational stakeholders are concerned with the high levels of student disengagement, evidenced by early school leaving, poor student behaviour, and low levels of academic achievement. The solution, student engagement, is a contested concept, theorised in a variety of different ways within academic literature. To further understand this concept, a phenomenographic study was conducted to map secondary school teachers’ conceptions of student engagement. Six qualitatively different ways of understanding student engagement were found. This research indicates that teachers do not hold similar understandings of what student engagement means. If the concept of engagement is to become educationally fruitful, the term must be more explicitly defined in educational research and government policy documents to promote shared understandings amongst stakeholder groups.