This chapter reviews first Catalonia’s history of language use, contested national identities, and related political issues, an understanding of which is necessary to comprehend the present dynamics. It devotes a subsection to present-day bilingual and multilingual language use patterns and choices involving immigration—a key characteristic of global cities—and the various subcommunities of Barcelonans. The chapter explores in some depth the most relevant language use and negotiation practices that have been the subject of considerable sociolinguistic research. Barcelona’s status as a global city may be said to have debuted symbolically with the 1992 Summer Olympics, which put the city in the world spotlight. Barcelona began to attract migrants from other regions, and by 1877 a quarter of the population came from outside Catalonia. The origins of the contemporary expatriate community are arguably in the 1950s when Barcelona and nearby coastal areas began to attract northern European tourists, which increased as Spain grew more prosperous and stable.