Examining Spanish as a lingua franca (LF) means exploring it within the terrain of its genetic, structural, and historic complexity. Concretely, it means relating processes and outcomes of linguistic change to specific situations of language contact and bilingualism, as well as to the role of Spanish as common vehicle of communication in economic and political contexts. This chapter focuses on recent research in Spanish as a LF, language variation, and contact linguistics. First, it considers situations where multilingual communication problems can appear: for those living in Afro-American settlements; those living in colonized and ethnically diverse territories; those living in border areas or bilingual enclaves; and those involved in transnational migration. Acquisition of Spanish by indigenous people in the context of bilingual intercultural education is also addressed here. Second, it accounts for the linguistic analysis of different forms of Spanish as a LF: spoken as a mother tongue, as a second language, or as hybridized forms. Third, the chapter considers some of the issues related to a theoretical framework for linguistic communication processes involving language contact based on a range of cases, mainly in the Americas. Other issues such as migration, urbanization, and the media are also discussed. This body of research demonstrates that approaching Spanish as a LF leads to a better understanding of the extent to which different historical and contemporary communicative circumstances produce different linguistic results with respect to development of a common medium of communication.