Experiential learning is essential for practical chemistry laboratory work, yet post-primary schools are increasingly constrained by cost, infrastructure, and safety requirements. We examine whether Virtual Reality (VR) can provide chemistry laboratory learning opportunities that are difficult to execute in everyday school practices through an 11-month, three-phase participatory co-design study involving 137 stakeholders (students, teachers, school leaders, parents, subject experts, and practitioners). In Phase One, we identified the pedagogical and deployment requirements for VR integration. In Phase Two, stakeholders evaluated an initial prototype to inform iterative design refinement. In Phase Three, we assessed an advanced prototype in authentic classroom contexts. Findings indicate significant gains in chemistry knowledge and procedural skills, alongside the development of transferable competencies (e.g., autonomy, critical thinking, and confidence). We further analyse how the use of VR reconfigured the classroom ecology, particularly teacher–student and student–student dynamics, and conclude with deployment lessons to inform a real-world rollout.