Burnout is a pervasive issue among medical students, with implications for their mental health, academic performance, and future careers in healthcare. Medical students face unique stressors, including heavy academic workload, emotional demands and insufficient support, which may contribute to burnout. In Nigeria, where medical students also grapple with socioeconomic challenges, the prevalence and causes of burnout remain underexplored. This study aims to investigate the prevalence of burnout, its contributing factors, and the role of support systems among medical students at the University of Ibadan, Nigeria. A mixed-methods approach was employed, combining both quantitative and qualitative data. The study involved 355 medical students from the University of Ibadan, spanning second to sixth years, who completed a self-administered online survey. The quantitative component assessed burnout using the Oldenburg Burnout Inventory for Students (OLBI-S) and social support using the Multidimensional Scale of Perceived Social Support (MSPSS). The qualitative component consisted of a focus group discussion (FGD) with 11 participants, exploring their perceptions of burnout, coping mechanisms, institutional support and factors contributing to burnout. Data from both components were triangulated for comprehensive analysis. The survey found that 81.1% of participants were classified as experiencing burnout, with high academic workload and lack of breaks as the primary contributing factors. Female students (91.7%, p < 0.001) and those in advanced years (600 level, p = 0.004) reported significantly higher levels of burnout. While 59.2% of students reported strong social support, particularly from family, only 3.9% had ever utilised the College's counselling services, highlighting a gap in institutional support. The FGD revealed that students rely heavily on peer support, family, social events and religious gatherings to cope with burnout. However, dissatisfaction with the College's counselling services was prevalent, as they were seen as ineffective and underutilised. The high prevalence of burnout among medical students at the University of Ibadan underscores the need for systemic reforms in medical education. Key recommendations include more frequent academic breaks, improved infrastructure and enhanced institutional support services. Efforts to address burnout should focus on fostering a more supportive academic environment. These findings are crucial for developing interventions aimed at improving the mental health and well-being of medical students in Nigeria and similar contexts.