Ibn Khaldūn (full name, Arabic: Abū Zayd ‘Abd ar-Raḥmān ibn Muḥammad ibn Khaldūn al-Ḥaḍramī; May 27, 1332 – March 19, 1406) is an Arab Muslim historiographer and historian, regarded to be among the founding fathers of modern sociology, historiography, demography, and economics.

He is best known for his book, the Muqaddimah (literally the "Introduction", known as the Prolegomena in Greek).

The book will influence seventeenth-century Ottoman historians like Ḥajjī Khalīfa and Mustafa Naima who will use the theories in the book to analyze the growth and decline of the Ottoman Empire.

Nineteenth-century European scholars will also acknowledge the significance of the book and consider Ibn Khaldun as one of the greatest philosophers of the Middle Ages.