Objective: The aim of this study was to examine the relationship between stress and various socio-demographic, health and behavioural factors among undergraduate students studying in an Australian university. Methods: A cross-sectional survey was carried out among first-year undergraduate students studying at Griffith University. Participants were recruited from four different academic groups (N=728). The questionnaire used in this study comprised of three sections: socio-demographic information, stress scale and a food frequency questionnaire. K-means Cluster analysis was performed to identify the major dietary patterns and multinomial logistic regression analysis was used to examine the factors associated with stress. Results: Nearly 53% of the students had some degree of stress with 37.4% experiencing moderate to severe levels of stress. The factors most strongly associated with having mild or moderate/ severe stress levels included being in a relationship [OR =1.71, 95% CI (1.02-2.87) and OR=1.61, 95% CI (1.06-2.44)], studying a non-health related degree [OR=1.68, 95% CI (1.03-2.73) and OR=1.51, 95% CI (1.04-2.19)], working ≥ 21 hours per week [OR=2.12, 95% CI (1.02-4.40) and OR=2.21, 95% CI (1.32-3.67)], and engaging in an unhealthy dietary pattern [OR=2.67, 95% CI (1.25-5.72) and OR=2.76, 95% CI (1.47-5.16)]. Being a female [OR=1.84, 95% CI (1.25-2.72)], living in a shared accommodation [OR=0.52, 95% CI (0.27-0.98)], rarely exercising [OR=2.64, 95% CI (1.59-4.39)], having a body mass index (BMI) of 25 or over [OR=2.03, 95% CI (1.36-3.04)], and engaging in a dietary pattern that was low in protein, fruit and vegetables [OR=1.72, 95% CI (1.06-2.77)] were also associated with having moderate/severe stress levels. Conclusion: This study found that more than half of the undergraduate students had some levels of stress. Both mild and moderate/severe levels of stress were associated with socio-demographic characteristics, risky health behaviours and poor dietary patterns. Our findings reinforce the need to promote healthy behaviours among undergraduate university students in order to maintain good mental health.