The purpose of this study was to provide a systematic scoping review of the research focussing on student-athletes’ mental health (MH). More specifically, we aimed to describe and synthesise: (a) the study and sample characteristics of the dual career (DC) and MH research literature, (b) the types of MH outcomes examined in student-athlete populations, (c) comparisons of student-athletes’ MH in relation to other populations of interest, and (d) the variables associated with student-athletes’ MH. Articles were collected from four databases: SPORTDiscus, PsycInfo, Scopus, and PubMed. In total, 159 studies spanning three decades met the inclusion criteria. Most studies were conducted within the North American collegiate context. The majority (62.5%) examined mental ill-health outcomes (e.g. disordered eating, depression, anxiety), 22.6% examined positive mental health outcomes (e.g. subjective well-being, psychological well-being), and 13.8% combined both perspectives. Most studies using non-student-athlete comparison groups found that student-athletes were at a similar or decreased risk for MH problems, although notable exceptions were identified. Finally, 49 distinct variables were associated with student-athletes’ MH. Most variables related to generic or sport-specific factors, with only a limited number of studies examining DC-specific factors. Findings from our scoping review are critically discussed in view of the existing literature. © 2022 Informa UK Limited, trading as Taylor & Francis Group.