Much debate exists concerning the factorial dimensionality of student well-being. We contribute to this debate by drawing on PISA 2018 data from a total of 61,722 students, 2528 schools, and nine countries. For our investigation, we test multiple associated measurement models for convergent, discriminant, and concurrent validity, model fit, and measurement invariance. For the PISA 2018 sample, we found very little variation in student well-being both between schools and between countries suggesting that variation in student well-being exists predominantly within respective school contexts. In addition, our findings support the notion that student life-satisfaction should be split into separate general and school-based factors in a Bi-Dimensional Life-Satisfaction Model. Moreover, results suggest that PISA 2018 data can be used to successfully measure a Four-Factor Hedonic Model of Student Well-being, tackling both cognitive (general life-satisfaction and satisfaction with school factors) and affective features (positive and negative affect). Finally, we propose a Five-Factor Integrative Model of Student Well-being that supports a broader conceptualization of student well-being that includes life-satisfaction, both positive and negative affect, and eudaemonia. We tested this model and found that it met the requirements for scalar invariance across male and female gender groups. However, for all 36 inter-country tests of measurement invariance, metric invariance was only reached nine times (25%), and scalar invariance was reached once (2.8%). Implications and recommendations for follow up research are provided.