Introduction: Internet addiction is one of the major issues among university students which affected not only their academic performance but also their sleep quality and eating behaviours. Thus, this study aims to investigate the association between internet addiction and eating behavior, with sleep quality among undergraduate students at Universiti Sains Malaysia (USM). Method: A cross-sectional study was conducted among 107 university students to obtain data regarding their internet addiction, eating behaviour, and sleep quality through a series of validated questionnaires. The Chi-square test, Mann-Whitney, and Kruskal-Wallis test had been used for the univariate analysis while binary logistic regression was the multivariate analysis. Significance was set as a p-value less than 0.05. Results: A total of 54.2% of the participants showed mild internet addiction and 59.8% of them had poor sleep quality. Severe internet addiction was significantly associated with highest scores in all the eating behaviour. Individuals who were overweight had the highest score for emotional eating. Furthermore, no association was found between internet addiction and eating behavior with sleep quality in both the univariate and multivariate analysis. Conclusion: Internet addiction may affect an individual`s eating behaviour and may potentially lead to several health complications in the future. Those who were overweight tend to be emotional eaters. Although, no significant factors were associated with sleep quality, future research should be done involving other parameters such as physical activity level, biochemical data and comorbidities.