This volume brings together evidence-based research, updating and advancing thinking on CLIL (Content and Language Integrated Learning) science across primary, secondary and teacher education. Drawing on both conceptual and empirical studies, chapters focus on the development of students’ disciplinary literacy in scientific and technical fields (biology, ecology, chemistry and physics) through classroom interaction and oral and written production. Authors examine how knowledge is constructed and communicated in multilingual science classrooms, exploring the use of Cognitive Discourse Functions, multimodality, Legitimation Code Theory, generative artificial intelligence, project-based learning, and issues of accessibility and inclusivity. Featuring research from Spain, Germany, Finland, Italy, Australia and China, authored by internationally recognised scholars in science, technology and language education, this book offers an essential resource for researchers, teacher educators and practitioners of CLIL STEM education.