This dissertation, Grand Visions: Nationhood and Citizenship in Postcolonial Nigeria, investigates the postcolonial dynamics of citizenship and nation-building in Nigeria. In Grand Visions, I argue that Britain, Nigeria's colonizers, invented Nigeria to be a corporation, not a nation; and because of this, postcolonial Nigerian leaders have to devise malleable strategies to imagine a nation and constitute citizenship from the invention they inherited from Britain. One of those strategies, I argue, is the production and circulation of grand discourses of nationhood and belonging through investments in mega infrastructures and foreign policy interventions. This strategy enables Nigerian leaders to constitute a modern nation out of Nigeria and project it as the "hope of the black race" in the mind of Nigerians and the world. On the other hand, I examine discourses in vernacular spaces that Nigerians employ to (re)negotiate and resist their leaders' visions of the nation. Chapter One ("Building Babel...") and Chapter Two ("Conceptual Clarifications...") introduce the concepts and theories that underpin this project. In Chapter Three, "Giant of Africa...," I foreground how Nigeria leverages its geographic and demographic size to produce and circulate "mega rhetoric" of giantness and leadership of Nigeria as the destined leader of the black race. The chapter builds on scholarship in constitutive rhetoric to examine "constitutive visions" of nationhood in Nigeria's postcolonial foreign policy. By focusing on foreign policy, I extend the tools of constitutive rhetorical analysis to an often-ignored (in rhetorical studies) but commonplace domain of nation-building: foreign policy. Furthermore, by investigating the dynamics of national identity formation in postcolonial Nigeria, I propose a rethink of "constitutive invitation." I argue that identity-constituting discourses (such as foreign policy statements) in heterogenous societies like Nigeria are not always targeted at "subjects" with a "shared history, motives, and a telos," as it is often imagined by rhetorical scholars. Chapter Four, "Constitutive Development..." highlights the fascination with developmental rhetoric in postcolonial Nigeria and underscores how the desire to create a national identity often translates into grand visions of development and infrastructure. This chapter argues that development in postcolonial Nigeria is both a metaphor and material to suggest progress and modernity. The chapter builds on the analysis of the built environment and speeches from Nigerian leaders. Here, I conclude that built spaces are rhetorical, especially in the work of postcolonial nation-building and defining notions of citizenship, because they have the communicative power to trigger a social imaginary of the nation as one in people's minds-spaces have the power to make people believe that they are a part of something bigger. Chapter Five, "(Un)making the Giant...," investigates constitutive identification and disidentification. Specifically, it examines the alternative spaces (pirate radios, Internet, protest grounds, etc.) where citizens respond to and renegotiate state-owned narratives about what it means to be a Nigerian. Here, I analyze the rhetorical practices of Nigerians in alternative spaces to reveal how they are questioning and renegotiating state-owned notions of nationhood and citizenship. This chapter also highlights how the Nigerian State identifies individuals and groups that resist the dominant narratives of nationhood. This chapter ultimately argues that alternative spaces that are out of state control enable Nigerians to perform citizenship in their own way and resist government ideas of the nation. Ultimately, in Grand Vision, I make two contributions to rhetorical studies and citizenship studies. First, I extend the conversations on the need for rhetoricians to expand the breadth of the field by applying the tools of rhetoric to realities in non-western rhetorical traditions. Second, I note that for postcolonial societies like Nigeria with huge ethnic and geographic diversity, the process of defining citizenship and nation-building is a difficult one. Such a process often contradicts popular notions of citizenship and nation-building and relies on the plasticity of rhetoric. This plasticity, I conclude, affords postcolonial African states and their citizens opportunities to re/imagine notions of citizenship and nationhood.