The integration of Generative Artificial Intelligence (GenAI) tools in English as a Second Language(ESL) classrooms has gained increasing attention in recent years. While these tools offer numerous advantages,such as personalized learning, automated feedback, and enhanced student engagement, their effectiveness largelydepends on teachers' perceptions and willingness to integrate them into their teaching practices. This literaturereview examines existing research on teacher perceptions of GenAI in ESL classrooms, focusing on both thepotential benefits and the challenges associated with its implementation. The review explores themes such aspedagogical applications, teacher attitudes, technological barriers, and ethical concerns. Findings suggest thatwhile many educators recognize the potential of GenAI for improving instructional efficiency and studentautonomy, concerns related to accuracy, digital literacy, and the risk of over-reliance on AI-generated contentpersist. Additionally, a lack of institutional support and teacher training remains a significant barrier towidespread adoption. The review highlights gaps in current research, particularly in non-Western ESL contexts,and emphasizes the need for further studies on professional development programmes and long-term impacts ofthe integration of GenAI in language learning.