This study aimed to explore the academic adaptation challenges experienced by Thai international students at UIN Walisongo Semarang, Indonesia. A qualitative case study was employed. Data were collected through in-depth interviews and participant observation involving Thai international students and analysed using Miles and Huberman’s interactive model of data condensation, data display, and conclusion drawing. The findings show that academic adaptation occurred through a gradual and integrative process. The university supported students by contextualising Indonesian academic language and learning norms, developing analytical and critical learning skills, facilitating classroom discussions and presentations, guiding academic writing, and introducing technology-supported learning through LMS, digital libraries, and electronic journals. Lecturer–student interaction and peer engagement with local students also strengthened adaptation. These supports helped students address challenges related to language, learning culture, academic norms, communication, and digital learning. Adaptation was therefore reciprocal, involving both student adjustment and institutional responsiveness while students maintained their cultural identities. The findings highlight the importance of comprehensive institutional support programmes that address linguistic, cultural, academic, social, and digital needs of international students in Islamic higher education.