Abu al-Hasan Ali ibn al-Husayn ibn Ali al-Mas'udi (in Arabic أبو الحسن علي بن الحسين بن علي المسعودي transl: Abu al-Ḥasan ʿAlī ibn al-Ḥusayn ibn ʿAlī al-Masʿūdī) (born c. 896, Baghdad, died September 956, Cairo, Egypt), was an Arab historian and geographer, known as the "Herodotus of the Arabs." Al-Masudi (in Arabic المسعودي) was one of the first to combine history and scientific geography in a large-scale work, Muruj adh-dhahab wa ma'adin al-jawhar (Arabic: مروج الذهب ومعادن الجواهر‎ translated The Meadows of Gold and Mines of Gems), a world history.

Al-Mas'udi tells us that he was born in Baghdad. He was a descendant of Abdullah Ibn Mas'ud, a companion of the Prophet Muhammad. However, we know little else about his early years. He mentions his association with many scholars in the lands through which he travelled. However, most of what we know of him comes from the internal evidence of his own works. Although Shboul questions the furthest extent sometimes asserted for al-Mas'udi's travels, even his more conservative estimation is impressive: