With increasing emphasis on employability in higher education (HE), there is an urgent need to understand how HE influences students' career interests. Vocational psychological interest literature has assumed that career interest is stable from adolescence to adulthood. Newer conceptions of interest, drawn from developmental-educational perspectives, instead emphasise the mutability of interest and the ways in which the environment can support its development. This study makes a novel contribution by extending a developmental-educational theory of interest to illuminate how students' career interests develop during university and influences on those career interests, suggesting ways to enhance development. We surveyed the 2019 bachelor's graduating class (n = 663) at a mid-ranked UK university offering both applied and pure programmes. Graduates indicated whether their career interests had changed during university, described their career interests 'when they started university' and what they were 'now', and explained what had affected their career interest during university. Most (61%), regardless of pure or applied studies, reported that their career interests had changed. Consistent with interest theory, the most common type of change was refinement within a Standard Industrial Classification (30%), followed by shifts to a different SIC (19%), becoming more decided (12%), or rejecting a plan, leaving them unsure (5%). The most common influences on career interests were the curriculum (46%), placements (14%), work experiences (7%), and co-curricular activities (6%). We conclude that career practitioners and academics need to consider the central role of disciplinary curricula in career learning and emphasise opportunities for work experiences in and outside the curriculum.