This paper explores how fairness was conceptualised by those responsible for admission to highly selective undergraduate courses at 17 universities in England. Fairness was conceptualised principally with reference to the traditional "meritocratic equality of opportunity" paradigm, which holds that university places should go to the most highly qualified candidates irrespective of social background. There was sympathy for an alternative "meritocratic equity of opportunity" model of fairness, involving the assessment of prospective students' qualifications in light of their socio-economic circumstances. However, our interviewees reported institutional resistance to reducing academic entry requirements for socio-economically disadvantaged students for fear of setting them up to fail, and acknowledged that existing pedagogical practices and academic support structures were inadequate for the task of supporting disadvantaged students entering with lower grades to fulfil their potential at university.