Abstract The aim of this study was to investigate whether nutrition knowledge and attitudes towards healthy eating are predictors of nutrition label use (NLU) and dietary quality in a diverse sample of university students in the UK. An online cross-sectional survey was conducted in 2013 among 500 students (mean age 24.9 years; 75% females) in 37 UK universities. Nutrition knowledge, attitudes, NLU and dietary quality were assessed using previously validated questionnaires. The majority of participants met dietary recommendations for fat, added sugar and fast food intake, and failed to meet recommendations for calcium, fibre, fruit and vegetable and dairy product intake, resulting in a median dietary quality score of 2.0 (score range = 0–8). Nutrition knowledge differed according to gender, age, body mass index (BMI), nationality and NLU. Attitudes towards healthy eating differed according to BMI and NLU and dietary quality differed according to gender. Nutrition knowledge and attitudes were significant predictors of NLU and dietary quality, with NLU mediating the latter relationship, whereas NLU, when controlled for knowledge and attitudes, negatively predicted dietary quality but did not have a significant independent relationship with diet. Future nutrition interventions to improve dietary quality in this sample of UK university students should focus on improving nutrition knowledge and attitudes towards healthy eating.