The chapter develops a critique of public space in terms of its role in social exclusion and inclusion. The role and significance of public space in contemporary urban society will be discussed through a broad, multi-dimensional and critical analysis of its political, economic and cultural aspects, both in physical and social terms. The chapter will then examine the effects and implications of social segregation and exclusion on the shape and nature of public space, and consequently on urban society. The effects include the decline and disappearance of public spaces in the privatization of urban space, in the growth of mono-functional and car-based suburbs, in the effects of consumerism that subordinate and transform the character of the public spaces, in the gentrification of the urban areas, and in the growth of social inequality that turns the public space into a place of homelessness and neglect. The chapter critically explores the potential contribution of public space to social inclusion: in social terms through the creation of spaces of sociability, where different groups can be present and meet; in political terms through the spaces of communication and action, where free expression and democratic debate can take place; and in economic terms through the space of exchange, with street markets and trade as a basis for social exchange. How far can these potentials go beyond rhetoric and transform the urban conditions? How far are these imagined contributions co-opted by global commercial forces?