Cultural diplomacy has historically been examined within a state-centric paradigm, embedded in colonial power structures and often reliant on Western frameworks in academic literature. This study seeks to introduce critical and decolonial perspectives by presenting a qualitative case analysis of Fandango Fronterizo, a non-profit organization at the Mexico-U.S. border, deeply rooted in a traditional form of community celebration. The research aims to explore Fandango Fronterizo’s diplomatic role by presenting its impact on local and migrant communities in the border region. Additionally, it analyzes the bottom-up organizational strategies that support this diplomatic role. The outcomes, values, narratives, images, and principles of these practices are assessed in their capacity to mediate intercultural communications among diverse societies, particularly in regions marked by asymmetric power dynamics like the Mexico-U.S. border. The study reveals that by providing safe spaces for intercultural dialogue and contesting colonial narratives through non-Western organizational systems and values, non-profit entities like Fandango Fronterizo can effectively influence the diplomatic arena, thereby challenging the Western state-centric cultural diplomacy model. Ultimately, this study proposes the conceptualization of “border diplomacy”, an alternative non-state and decolonial form of cultural diplomacy inspired by Mignolo and Tlostanova’s border thinking theory.