The balance between study life and personal life has been recognized as one of the important indicators of student well-being. This study aims to examine the mediating and moderating roles of study-life balance in predicting student well-being using the study demands-resources framework. The study employed a multilevel quantitative diary design, with data analyzed using hierarchical linear modeling. Data were collected from 79 undergraduate students attending public universities in Malaysia. Participants completed six sets of diary questionnaires over two consecutive weeks (79 participants * 2 weeks * 3 days = 474 diary data points). The results showed that study demands had a negative relationship with daily study-life balance, while study resources had a positive relationship with daily study-life balance. The analysis also revealed the negative association between study demands and daily student well-being as well as the positive association between study resources and daily student well-being, were mediated by daily study-life balance. However, the moderating role of study-life balance was found only when predicting the relationship between study demands and daily student well-being. Study-life balance may act as a buffer when individuals face stressful conditions due to high demands at university, while no effect was found when adequate resources were present. Overall, the research findings highlighted the importance of a balance between study and life for university students as one of the main determinants of well-being.