Student mental health is an increasingly pressing concern in higher education globally, yet efforts to deal with this issue are often hampered by inconsistencies in defining and measuring mental health and wellbeing. This systematic review synthesizes empirical research examining the measurement approaches used to assess mental health and wellbeing among university students. Thirty-one high-quality studies published between 2008 and 2024 were identified through rigorous screening and quality appraisal processes. The review explores the purpose, conceptual coherence, psychometric robustness, and educational relevance of instruments used to assess student mental health (most commonly operationalised in the literature as psychological distress) and psychological or subjective wellbeing (most commonly operationalised as flourishing, thriving, life satisfaction, and quality of life) employed across diverse higher education contexts. Findings reveal a predominant reliance on clinical symptom-based tools such as the DASS-21, PHQ-9, GAD-7 and PSS-10, while measures of positive wellbeing and context-sensitive tools tailored to higher education settings remain comparatively underutilised. Few reviewed studies embedded educational constructs such as academic engagement, self-efficacy or belonging into their assessment frameworks. This review argues for a shift towards more integrative, theory-informed approaches that combine assessments of psychological distress with indicators of positive wellbeing and educational experiences. By doing so, university policies and practices can move beyond reactive support models towards designing educational environments that promote and support overall student wellbeing.