There is a growing issue of university students not being able to afford or have access to nutritious food. Although research reveals that food insecurity negatively impacts student well-being and engagement, few studies have explored its impact on academic performance. Most of these studies use self-reported measures of academic performance in college samples from the United States. The current study is novel in that it explores food insecurity in an Australian university sample and uses actual academic performance (weighted average marks; WAM) rather than relying on self-reported grades. We also consider the role of psychological distress in the relationship between food insecurity and academic performance. Participants comprised 664 undergraduate students aged 18 to 25 years at a public university in Melbourne, Australia. One-quarter of students (25.5%) were classified as food insecure. Renting, receiving government benefits, having a disability and being older were positively associated with food insecurity and food insecurity was associated with poorer academic performance and increased psychological distress. Psychological distress partially mediated the relationship between WAM and food insecurity, meaning that students experiencing food insecurity are more likely to experience increased psychological distress which then impairs their academic performance. The prevalence of food insecurity in university students suggest that interventions aimed at improving both mental health and access to food could serve to enhance success at university, especially for students who cannot afford or do not have access to nutritious food.