Despite the vigorous debate on the extent, modalities and impacts of public space privatization, there have been few analyses of the processes of its emergence in specific places. Based on 36 stakeholder interviews and desk research, this paper does so through an analysis of how the Martim Moniz square, in Lisbon, became the city’s first square under private management in 2012. To do so, the paper goes through the local governance context and the importance of convivial public spaces as a political objective, leading to regular partnerships with non-state actors. The square is adjacent to Mouraria, a derelict neighbourhood that was a testing ground for the city’s new urban policies. The square’s private management scheme – branded the Mercado de Fusão – rather than a rupture with existing practices, is the result of a coincidence of interests of both actors. Moreover, it reassembles typical local policy responses and the company’s expertise in a unitary management scheme. The seamless implementation of the Mercado is made possible by the pre-existing relationship between the company and the municipality. The paper thus shows that there is no fundamental shift towards private governance in Lisbon. Rather, it is the generalized commodification of public spaces resulting from the emergence of conviviality as a political objective that opened up the conditions for the square’s privatization. The relationship between conviviality as a political objective and privatization is presented as a promising subject for further research.