An increasing amount of scholarly literature exists that examines the relationship between students and universities, and their role in university governance and quality assurance of their higher education experiences. The traditional mechanisms for involving students in university governance -- for example, through representation by student associations -- have been challenged and expanded as part of a broader movement towards students as partners and co-creation of their educational experiences. This paper provides a critical review of student engagement in university governance and quality assurance systems, using the Australian system as a grounding example, and with particular focus on student equity and the increasing diversity of the student body, and its implications for quality assessment and assurance. Our critical review of the literature suggests that there is still progress to be made in integrating the complex roles students can assume within universities, but that considerable opportunities exist in meeting the challenges of massification, student diversity and the structural barriers some students face to success in higher education, provided that the full diversity of the student body can meaningfully engage in student governance.