The global resurgence of nationalism has challenged the neoliberal ideal of a borderless world, where the nationality of businesses would become irrelevant. While nationalism can foster social cohesion and drive progress, it also risks deepening societal divisions and inciting conflict—dynamics that organizations can no longer afford to overlook. In this talk, I introduce the theory of Organizational Nationalism (OGN), which repositions organizations not merely as passive recipients of nationalist pressures or geopolitical risks, but as active agents in shaping nationalistic ideologies, values, and policies. The OGN theory comprises three key components: (1) a four-dimensional framework capturing the core content of organizational nationalism, (2) four archetypes of OGN, representing its expression as either an organizational ideology or strategic orientation, and (3) the intermediary role of OGN in linking state-driven nationalism and individual-level nationalistic attitudes. Organizational nationalism can be empirically measured through computational linguistics, leveraging advances in artificial intelligence and large language models (LLMs). I will present computational analyses of corporate nationalism among Chinese and U.S. public firms from 2020 to 2023, revealing the growing prevalence of nationalistic rhetoric in corporate discourse, as well as the antecedents and organizational consequences of firms’ engagement with nationalism.