When is inequality felt as social difference? Charles Tilly argued that it is not simply the extent of inequality that matters but how it is organized. I build on this account by incorporating a view of spatial boundaries as organizing social interactions and directing perceptions of groupness; that is, as helping define the actors and contexts at stake. I argue that the spatial organization of inequality affects how we perceive and experience it. Where parties are unequal and in competition over resources, their segregation may promote categorical inequality, while their integration may inhibit it. I trace these obverse trajectories in the cases of Manila and Singapore. In Manila, social inequality increased despite economic inequality decreasing, whereas in Singapore, social inequality decreased despite economic inequality increasing. I show that spatial organization in the form of segregation and integration, respectively, played a significant role in the sharpening and muting of social boundaries.