This paper explores the historical moment in which the concept of a “national language” began to spread among Armenians in the Ottoman Empire. It does so by examining the establishment of educational associations aimed at changing the language practices of non-Armenophone Armenians in three parts of the Ottoman Empire: Aleppo, Kayseri and Diyarbekir. I argue that these associations were part of a cultural nationalist movement that gained momentum in urban centers beginning in the 1840s. It was in this ideological atmosphere that non-Armenian language practices began to be viewed as problematic, as they ran counter to the intelligentsia’s new conceptualization of an Armenian identity rooted primarily in language rather than in religion. Through an examination of the founding principles of the associations, I show how their leadership sought to introduce these communities to a new ethnolinguistic understanding of Armenian identity in an attempt to integrate them into a national community in the making. Relying on untapped Armenian-language printed materials, this paper shines a spotlight on the unexamined dynamics of Ottoman Armenian cultural nationalism and draws attention to the role of Armenification in the formation of an Ottoman Armenian national identity. Existing scholarship on Armenian nationalism has focused overwhelmingly on political nationalism and on the work of Armenian revolutionary parties in the final decades of the Ottoman period. Traveling deeper into the nineteenth century, this paper draws on the concept of cultural nationalism, an ideology devoid of overtly political aspirations that emphasizes the development of a national consciousness rather than a nation-state. With regard to Armenian identity formation, research has focused less on the construction of Armenian identity and much more on its erasure in the form of Turkification. Here, I look not at Turkification but Armenification, framing it within the rise of Armenian cultural nationalism. In particular, I show how the creation of an ethnolinguistic conception of Armenian identity prompted intellectuals to mobilize in hopes of changing the varied language practices of Armenians in the Empire, thereby, from their perspective, Armenifying them. This language-based process of Armenification entails writing back into history the notion that Ottoman Armenians were linguistically diverse, with many having little knowledge of any form of Armenian and using Turkish, Kurdish or Arabic as their primary or sole language. While Ottoman-era Armenian-language sources are replete with references to this linguistic heterogeneity, scholars have largely overlooked non-Armenophone Armenians or have misleadingly portrayed them as historically aberrant.