The success or failure of governance of a nation lies on the tone and collaborative capacity of language
used. This work seeks to unveil ethno-linguistic loyalty and the paradox of language for sustainable
development in a multi-ethnic Nigerian society. Drawing on social psychology theory of social identity and the concept of linguistic fragmentation, the theory examines how people define themselves and perceive others based on group membership, while the concept of linguistic fragmentation argues that language can create communication gaps and hinder effective governance in nation building. The
framework is deemed proper for this study because it argues that extreme attachment to a people’s
linguistic group and language can lead to discrimination and tensions among different linguistic groups, making it challenging for a nation to work together towards common goals. Through analysis of various happenings and instances in Nigeria and other parts of the world, this study examines how language can impact on a sustainable national development. In furtherance, it discuss the challenges that arise from ethno-linguistic loyalty and lack of dialogue, as well as make recommendations for effectively managing
and promoting linguistic diversity within a nation. Ultimately, the essay highlights the importance of
embracing linguistic diversity while simultaneously fostering national identity.