ABSTRACT The UK 2019–2024 Conservative Government’s ambition was for all schools in England to be part of a multi-academy trust (MAT), a publicly funded body outside of local authority control (Department for Education 2022a). The preference for larger, geographically widespread MATs has resulted in a centralised system, where governance and management of schools is potentially detached from local views and concerns, leading to questions over the legitimacy of these organisations as providers of education. Through the use of phenomenology and organisational theory, this paper explores conceptions of legitimacy for stakeholders in four MATs. It highlights the fragility of an education system over-reliant on the reputation and expertise of the founding CEO, and trustees who often lack educational and pedagogical knowledge, with limited understanding of local issues. This article argues that the lack of plurality and representation on trust boards, limits agency for academy leaders and diminishes space for local voices to be heard. The inadequacies of applying organisational theory to identify legitimacy are exposed. A more insightful model is presented, including a set of ‘MAT legitimacy indicators’: appropriate knowledge, expertise and values of those in management and governance; cultural and demographic representation in governance; plurality through diversity of voice and dissensus.