The One Health approach often reaches classrooms through Environmental Education (EE), which aims to guide society's response to halt the ongoing environmental, health, economic, and value crises. However, this goal has not been achieved. One reason is that EE teaching has traditionally focused on learning isolated ecological concepts and standardized solutions. Additionally, teacher training has tended to neglect didactic content knowledge, resulting in a reduced capacity to influence students' concerns and behaviours. Despite EE's multidimensional nature, ineffective didactic strategies have prevented students from acquiring the systemic vision needed to address eco-social problems and devise sustainable solutions in line with the Sustainable Development Goals (SDGs). In this context, this work proposes strategies to improve EE teaching through the One Health approach to achieve Transformative Environmental Education (TEE). The practical examples presented demonstrate successful EE initiatives that integrate One Health into classrooms using effective methods promoted by Science Education research. Effective EE should inspire critical thinking, empowerment, and student reflection, fostering a deep understanding of socio-environmental issues and innovative solutions from early education to create committed citizens. Therefore, achieving TEE requires reforming teacher training programs to strengthen didactic competencies and promote transformative educational practices, emphasising systems thinking, scientific and epistemic practices, and environmental justice awareness.