Objective The aim of this study was to examine the relationship between stress and food selection patterns by sex among first-year undergraduate students studying in an Australian university. Methods Participating in this cross-sectional study were 728 (331 men and 397 female students) first-year students, ages >18 y, attending the Gold Coast Campus of Griffith University. Data were collected using a self-administered questionnaire consisting of three sections: sociodemographic information, stress measures, and a 7-d food frequency questionnaire. Results More than half (52.9%) of the participants were found to suffer from some level of stress, with relatively more female students (57.4%) suffering than men (47.4%). Men who experienced mild to moderate levels of stress were two to three times more likely to eat cereal foods (P < 0.01), fish/seafood (P < 0.001), and protein powder (P < 0.05). They also tended to eat more meat alternatives (P < 0.05), highly processed foods (P < 0.05), and to drink more alcohol (P < 0.05) than unstressed male students. However, they were less likely to consume vegetables and fruit (P < 0.05) compared with their unstressed counterparts. The trend analysis results indicated significant dose-response patterns in the relationship between stress level and consumption of cereal food, meat alternatives, vegetables and fruit (negative trend), highly processed food, protein powder, beverages and alcoholic beverages (all P < 0.05). Female students who experienced mild to moderate stress were 2.22 times more likely to eat processed food (P < 0.01) than unstressed female students. Female students who experienced severe stress were less likely to consume meat alternatives (P < 0.05) than their unstressed counterparts. Significant dose-response trends were found in the relationship between stress levels and the consumption of meat alternatives, vegetables and fruit (both negative trends), and processed food (all P < 0.01). Conclusion These results demonstrate a clear difference in food selection patterns between stressed male and female students, with stress being a more significant predictor of unhealthy food selection among male students. Further research is needed using a qualitative approach to understand how stress and eating behavior are related in university students.