The rapid integration of artificial intelligence (AI) in educational settings presents both unprecedented opportunities for personalised learning and significant ethical challenges. This paper argues that teachers play a central role in guiding the responsible and ethical use of AI in schools. It examines how teacher intervention can prevent misuse, promote academic integrity, and foster critical thinking and digital literacy among students. The discussion highlights the importance of modelling proper AI use, incorporating AI literacy into curricula, and establishing clear classroom guidelines. Furthermore, the paper explores the broader benefits of teacher-guided AI integration, including enhanced learning outcomes, preparation for future careers, equitable access, and the development of responsible digital citizenship. Counterarguments regarding student independence, teacher preparedness, and potential constraints on creativity are addressed and rebutted, emphasising that ethical guidance strengthens rather than limits student engagement and innovation. The paper concludes that ethical instruction in AI use is indispensable and that teachers, through intentional guidance and professional development, are key to cultivating a culture of integrity, accountability, and critical engagement with technology. Recommendations are provided for integrating AI literacy programs, supporting teacher development, setting clear policies, and encouraging reflective and responsible use among students. Overall, the study underscores that the ethical and effective adoption of AI in education is not optional but essential for preparing students to navigate a technology-driven world responsibly.