The International Institute of Islamic Thought and Civilisation (ISTAC) is a research and postgraduate institution of the International Islamic University Malaysia (IIUM) located at Pesiaran Tuanku Syed Sirajuddin off Jalan Duta, Kuala Lumpur, Malaysia. It was founded in 1987 by Syed Muhammad Naquib al-Attas, a Muslim philosopher.
ISTAC can be considered an "Islamic university", based on religious principles, seeking to integrate the various degrees it offers within an Islamic world outlook, In that sense, it is comparable to Catholic or Protestant universities aiming at a similar result.
Its curriculum specialises in Islamic thought, civilisation and science at master's and doctoral levels. Its programme also covers the study of the world's major religions and of the modern secular world of today. It is notable for the international character of its academic staff as well as the student body.
In 2015, ISTAC name was changed to Ibn Khaldun International Institute of Advanced Research (ISLAH). Later, all programmes based at ISLAH were merged with IRKHS courses, and its professors and students relocated to International Islamic University Malaysia main campus in Gombak.
The compound where the 'beacon at the crest of a hill' once stands, now is known by Centre for Strategic Continuing Education and Training (CRESCENT). However, the famous ISTAC library remains, bearing the name Syed Muhammad Naquib al-Attas Library, as recognition of a legacy of its founder.