The purpose of this mixed-methods research is to investigate how student voice takes place in relation to classroom practice in Irish post-primary schools, and the views of both school staff and students on this student voice. In doing this, particular attention is paid to the patronage and socio-economic context of schools. Several contributions to knowledge are made: a heuristic device as a starting point for future research in the Irish context is developed and presented; how student voice is likely to be enacted differently in different types of schools and schools in different settings is explored for the first time; and stakeholders’ views on student voice being used in relation to classroom practice in Irish post-primary schools are explicitly explored. This research is the first research of its kind in Ireland, providing unprecedented knowledge and insights, and will be of interest and of use to those involved in teaching, leadership and governance in schools, research in higher education, and policy and advocacy in the public and voluntary sectors. Through interviews with 101 participants in seven case study schools and a subsequent survey of principals that yielded 95 responses, this research highlights how, inter alia, students are consulted to different extents in different schools; student voice can be used to monitor teachers; and most stakeholders in Irish post-primary schools are against the idea of students being consulted on teacher performance.