As concerns about student mental health have increased, policy aims have moved towards a ‘whole-university’ approach. The 2017 Universities UK #Stepchange framework made this principle a formal part of policy initiatives and legitimises it via its calls for action. The policy distributes responsibility for mental health support across the institution, highlighting four key reasons for intervention: risk, regulation, success and policy. However, little is known about how this policy has been translated into practice and how activities for mental health have been adopted into the everyday work of higher education (HE) institutions. This article explores how one service common across all HE institutions, the academic library, has interpreted this call to contribute to student mental health. Using data from a national UK survey alongside policy analysis, this article investigates the strategic rationale and the practicalities of engaging with a whole-university approach. Findings show that local concerns often drove activity, which could be mapped to some aspects of a whole-university approach, but that the boundaries of professional expertise and resources were key considerations in accepting distributed responsibility. More broadly, mental health support was recontextualised to include wellbeing; this made it easier to adopt some aspects of a whole-university approach but focused on prevention rather than risk and regulation. As a result, activities being conducted in practice did not align directly with the whole-university approach.