Following a period of close to a century when the Irish language was placed at the margins of the education system under British rule, there was a radical change in curriculum provision following political independence in Ireland in the 1920s. The importance of the Irish language in defining sovereignty, national identity, and nationhood in the Irish Free State was central to these curricular changes. Within months of the achievement of political independence, curriculum policy was revised to include provision for the teaching of the Irish language to all pupils in primary schools as well as the use of Irish as the medium of instruction in infant classes (the first two years of primary school). The education system became the linchpin in the political and cultural campaign to restore the Irish language as the vernacular. This paper critically examines how nationalist thinking in Ireland, which had its origins in nineteenth-century European discourses, impacted on curriculum decisions pertaining to the Irish language in the early 1900s. Focusing on the interrelationship between nationalism, language, and education, it traces the process and provisions of curriculum development in Ireland in the 1920s. Overall the paper argues that the influence of nationalism as understood in the wider European context of the time shifted emphasis in Ireland away from bilingualism (Irish and English languages) to the revival of the Irish language in the 1920s, primarily through the education system, to add political legitimacy to the new Irish Free State.