Student engagement and university belonging are central to student success, yet little is known about how they relate to one another in the ebb and flow of everyday university life. Most research treats engagement and belonging as relatively stable or examines them at a single point in time, leaving unanswered the question of whether short-term changes in one drive changes in the other. Although some longitudinal work has captured week-to-week variability, no study has tested whether fluctuations in engagement predict corresponding shifts in belonging. This study directly addresses that gap by modelling the dynamic relationship between engagement and belonging across the semester. First- and second-year psychology undergraduates at the University of Western Australia will complete surveys at four time points between Weeks 2 and 8 of semester via a staggered rolling design, with data collected across two semesters. Engagement will be assessed across academic and social domains, and belonging measured through perceptions of inclusion, acceptance, and being valued. Students will also provide brief qualitative reflections on contextual factors shaping their experiences. Analyses will include multilevel within-person models to test whether week-to-week changes in engagement predict changes in belonging, and structural tests to examine whether both constructs are multidimensional and stable in structure but variable in intensity over time. By modelling engagement and belonging dynamically, this study will be the first to test a predictive week-to-week model of engagement on belonging, identifying when, where, and how these processes shift during semester. Findings are expected to add to evidence that engagement and belonging are fluctuating states rather than stable traits, while uniquely demonstrating the predictive influence of engagement fluctuations on belonging fluctuations. In doing so, the study will provide practical insights by identifying critical periods when targeted engagement strategies are most likely to strengthen belonging and support student adjustment in higher education.