This study explores workplace supervisors’ perceptions of student mental health during their work-integrated learning (WIL) programme and their role in supporting these students. Research methods involved analyzing online survey (n = 80) results and semi-structured recorded interviews (n = 11) with supervisors from the MSc WIL programme (Nutrition and Dietetics) at Massey University, New Zealand. Supervisors noted student’s mental health being influenced across individual-, relationship- and organizational areas. However, most supervisors (69%) only felt ‘somewhat confident’ or ‘not confident at all’ in recognizing signs of anxiety and depression, and almost all (92%) had no formal mental health training. Supervisors supported student mental health during WIL by creating a sense of belonging for students within the workplace, using appropriate supervisory styles which align with mentoring and coaching techniques, and adopting culturally responsive supervision. Potential strategies identified to support workplace supervisors in their role were mental health first aid and resilience training.