This article systematically reviews the studies integrating sustainability into English Language Teaching (ELT), underlining the critical role of education in addressing global environmental challenges through language learning. Through an extensive literature review encompassing empirical studies, theoretical articles, and case studies from 2013 to 2023, we evaluate the methodologies for incorporating sustainability in ELT, identify the challenges faced by educators, and propose practical solutions. Key findings demonstrate various effective approaches, such as interdisciplinary curriculum designs, innovative classroom activities, specialized teacher training, and novel assessment methods, which enhance language proficiency and significantly raise students’ language-learning awareness. Despite challenges such as limited resources and alignment issues between sustainability topics and language-learning objectives, strategies like developing open educational resources and professional development programs have shown promise in overcoming these obstacles. The review underscores the importance of embedding sustainability in ELT to foster informed, responsible global citizens and highlights future research directions to further this aim. It calls for continued innovation, research, and policy support to fully realize the potential of ELT in contributing to a more sustainable future.