In this paper I offer an analysis of the critical place that “informality” occupies in the urbanistic reordering of the “Cidade Olimpica” Rio de Janeiro. Contextualizing it in Brazil’s claim to an emergent geopolitical position as a BRICS country, I explore how this reordering intersects with spatial confinement of the urban poor. I draw from examples of real estate entrepreneurialism, resettlements and territorial conflicts in Barra da Tijuca and Jacarepaguá, two of Rio de Janeiro’s rapidly transforming areas. Drawing from Judith Butler´s concept of performativity (1993), I introduce informality as a performed role and volatile ascription allowing us to understand how urban actors bargain their influence vis-à-vis unstable urban planning processes. In the making of the Olympic City, informality functions (1) as a signifier of what is perceived to be a threat to justify the stigmatization and subsequent confinement of marginalized communities as a result of local infrastructure projects related to mega-events; (2) as a signifier to justify defensive interventions against the municipal government and real estate developers by an organized upper middle-class; and (3) as a signifier around which resistances and alliances form between activist groups, researchers and NGOs on the edges of the urban fabric. Correlating urban informality and spatial confinement allows for an understanding of a spatialized, contested and performed stateness underlying city branding and also of the political mobilization of the urban poor despite of hegemonic marginalization in cities of the Global South.