<p>Environmental Education (EE) is fundamental for fostering sustainable development, yet its integration into secondary school curricula in South Africa remains inconsistent. This qualitative case study investigated how different school stakeholders (principals, subject advisors (district curriculum specialist), heads of departments and teachers) conceptualise EE and how their understanding influences curriculum planning and implementation in KwaZulu Natal. Data were collected through semi-structured interviews (<i>n</i> = 11), classroom observations and document analysis across three purposively selected secondary schools known for EE activities in KwaZulu Natal. Thematic analysis revealed that stakeholders often equate EE with basic school cleanliness and awareness campaigns, showing limited recognition of its interdisciplinary and pedagogical dimensions. EE was largely treated as an extramural add-on rather than a systematically integrated academic component. Curriculum management was predominantly compliance-driven, characterized by hierarchical oversight and routine monitoring, with little emphasis on collaborative planning or experiential learning. Notably, none of the participants connected EE to broader frameworks such as Education for Sustainable Development (ESD) or the Sustainable Development Goals (SDGs). These findings point significant gaps between policy and practice. The study calls for targeted professional development, stronger instructional leadership and supportive communities of practice to bridge the gap between EE awareness and effective classroom practice. Strengthening stakeholders’ conceptual understanding and leadership capacity, schools can move beyond superficial awareness toward cultivating genuine environmental literacy across the curriculum.</p>