Over the course of the 20th century, Iraq became a hub of debates and policies relating to the idea of an “Arab World.” These theories and practices were particularly evident in the field of education. From fascist-inspired, government-organized youth organizations to high-brow salons where educators, leaders and functionaries mingled, the concept of the Arab World was bandied about, defined, redefined, and at times taken for granted. Historians have explored the inextricable connection between concepts of the Arab world and ideas of Arab nationalism. Analyses tend to concentrate on Arab nationalism’s origins, validity and staying power. Alternatively, scholars have explored the Arab world’s links to Arab nationalism by investigating how Pan-Arabism overlapped with or opposed Iraqi nationalism. These discussions, however, often elide the ways in which individual and influential thinkers defined the Arab World specifically, as opposed to concepts such as the Arab Nation, Pan-Arabism, Arab nationalism or Arab Homeland. This paper examines how key Arab intellectuals and educators in Iraq conceived of the Arab World from the first decades of the 20th century to the early years of Ba’thist rule. In addition to providing a brief intellectual genealogy of the Arab World as an idea, I argue that a shift from a loose and inclusive Arab World coalesced into a rigid conception of nation states, to be allied in formal ways rather than loose cooperative initiatives. Important thinkers promulgated these changing beliefs through teaching and textbooks in Iraq’s expanding educational system. I analyze Arab educationalists from within and beyond Iraq, including Sati al-Husri, Darwish al-Miqdadi, Matta ‘Akrawi and Fadhel al-Jamali. Using educational journals, memoirs, speeches, scholarly works and textbooks, this paper pinpoints shifts in the idea of an Arab World over time. “Educating the Arab World” examines interpretations of the Arab World, as well as the ways in which those interpretations were presented to Iraqi society through schooling. My approach underscores differences between loosely-defined notions of Arab Unity and the world meant to be united during the Hashemite-era on the one hand and the growing strictness of Ba’th rule and ideology during the 1960s on the other.