This paper introduces the ADAICLE Corpus, a learner corpus compiled from written productions by Primary and Secondary Education students participating in the national project Evaluación Nacional de la Enseñanza Bilingüe en España (ENEBE). The corpus documents how students in Content and Language Integrated Learning (CLIL) contexts use English to construct disciplinary knowledge and engage in academic discourse practices, thus offering new empirical evidence on language use in school-based bilingual education. The article first provides some previous research on corpus linguistics and learner corpora, followed by a detailed account of the design and compilation of the ADAICLE Corpus, including test design, piloting, and implementation in schools across the Autonomous Community of Cantabria (Spain). It then outlines the corpus’s structure and content, including the number of participants, tasks, schools, and word tokens. The study concludes by discussing the corpus’s relevance and potential applications for future research, pedagogical innovation, and policy development in bilingual and CLIL education.