Purpose: This study aims to understand university students' perception and engagement with sustainable food practices and the relationship with diet quality. Design/methodology/approach: A cross-sectional survey assessed Australian university students' sustainable food perceptions and purchasing behaviours, diet quality using the validated Australian Recommended Food Score and attitudes towards on campus sustainable food options. Findings: Of respondents (n = 197; 63% female), over half (58%) perceived it was important to purchase sustainable foods. These students were eight times more likely report purchasing sustainable foods (OR: 8.1; 95%CI 4.2-15.7; SE: 0.3; p < 0.001) and had significantly higher diet quality (Beta coefficient: 2.9; 95% Confidence Intervals 0.4-5.4; Standard Error: 1.3; p = 0.024). Students who reported frequently purchasing all types of sustainable foods, except organic foods, had significantly higher diet quality. Few students perceived there were sufficient sustainable food choices on campus (19%), but most supported the development of an edible campus (80%). Originality/value: The results highlight the potential impact of promoting sustainable food options and creating a supportive campus food environment towards improving students' diet quality.