<p>Adolescent mental health has become an increasingly important concern in educational contexts, yet students’ lived experiences of learning mental health literacy through digital platforms remain underexplored, particularly in developing countries. This study explored Vietnamese secondary school students’ experiences of participating in an eight-week Virtual Learning Environment (VLE) course designed to enhance mental health literacy. A descriptive phenomenological approach based on Colaizzi’s method was employed to examine how students perceived and interpreted their learning experiences. Semi-structured interviews were conducted with eight students who completed the course, and the interview data were analyzed following Colaizzi’s procedure. The analysis revealed four experiential themes: Vague initial perceptions and stigma about mental health; Experience of psychological safety when learning in the VLE; Development of mental health self-care skills; Transformation of positive attitudes towards adolescent mental health issues. These findings suggest that a well-facilitated VLE can create a supportive learning space that encourages reflection, emotional awareness, and dialogue about psychological well-being. The study provides insights for educators seeking to integrate mental health literacy into school programs through digitally supported learning environments, particularly in contexts where school-based mental health education is still developing.</p>