["British Journal of Educational Technology, EarlyView. ", "\n\nAbstract\nDespite increasing interest in using Generative Artificial Intelligence (GenAI) in education, little is known about how students with disability engage with GenAI to support their own learning. This study investigates the potential of ChatGPT to support the learning agency of adolescents with disability in a secondary science classroom in Australia. Guided by sociocultural and socio‐material conceptualisations of agency, the study explored the mediated choices and capabilities of three students with disability to use ChatGPT to facilitate their learning. The study was conducted in a class comprising students of varying ages clinically diagnosed with diverse learning needs. Data sources included student interviews, the students' conversations with ChatGPT, teachers' lesson worksheets and video recordings of the lesson. Thematic analyses reveal that while students expressed clear and meaningful choices to use ChatGPT to support their learning, they faced metacognitive challenges and cognitive constraints, resulting in a misalignment between their choices and actual capability. The findings identify key theoretical perspectives and practical considerations for supporting students with disability in using GenAI to develop their learning agency. The study recommends customising GenAI for specific learning needs in line with its function as a cognitive prosthesis for students with disability and for better alignment with Universal Design for Learning, thereby supporting students' learning agency.\n\n\n\n\nPractitioner notes\nWhat is already known about this topic\n\nThe development of students' learning agency has been widely explored in the secondary context, but not for students with disability.\nThere is increasing interest in using Generative AI (GenAI) to support inclusive education.\nCurrent theoretical frameworks can inform the exploration of the learning agency of students with disability using GenAI.\n\nWhat this paper adds\n\nForegrounds the learning choices of students with disability as indicators of their emergent learning agency.\nIdentifies learning challenges facing students with disability that misalign their learning choices and capabilities.\nExamines GenAI's potential as a socio‐material mediator facilitating the material and relational agency of students with disability.\n\nImplications for practice and/or policy\n\nConsulting students with disability on how GenAI can support their learning, providing opportunities for them to express their learning preferences.\nCustomising GenAI tools in line with the Universal Design for Learning guidelines to address the specific learning challenges of students with disability.\nClarifying the roles of teachers and education assistants in facilitating the learning agency of students with disability in light of customising GenAI to mediate their learning agency.\n\n\n\n\n"]