This paper defines transformative language teaching for sustainability (TLS) and shows how contemporary, learner-oriented language teaching can foster important competencies and skills needed to reach the goals of education for sustainable development (ESD). The main aim of our approach is to integrate transformation-oriented ESD into language teaching in a way that considers and utilises the special features of language teaching and learning. We discuss the substantial possibilities that language education offers to ESD and propose a transformation-oriented ESD framework as the foundation for TLS, covering the linguistic and cultural features of sustainability that are central to language teaching and learning. Finally, we outline the pedagogical implications for TLS related to subject matter content and methods, that is, how language teachers can use learner-oriented language teaching methods to integrate ESD in their lessons. We propose a theory-based interdisciplinary model for the implementation of TLS in language education and language teacher education.