Despite profound changes to the higher education sector in the UK over recent years, which have tended to emphasise the role of prospective students as active choosers within a marketplace and encourage higher education institutions (HEIs) to place more emphasis on student engagement and representation as a means of improving the quality of the learning experience, the role of students' unions has remained largely unexplored. To start to redress this gap, this paper draws on a UK-wide survey of students' union officers and a series of focus groups with 86 students and higher education staff in 10 case study institutions. It outlines the ways in which students' unions are believed, by those closely involved with them, to have changed over recent years, focusing on: the shift towards a much greater emphasis on representation in the role and function of the students' union; the increasing importance of non-elected officers; and the emergence of more cooperative relationships between the students' union and senior institutional management. The article then discusses the implications of these findings for both our understanding of the political engagement of students, and theorising student involvement in the governance of HEIs.