This article presents the sociolinguistic aspects of Spanish in contact with Basque in the Basque Country and Navarre. It will take a look at the historical reasons for the presence of Spanish in both territories, the relative status of the two languages, the linguistic characterization of the Spanish in these bilingual areas, or the linguistic results of the contact, the domains where Spanish is used, and so on. It will also detail the language-related legislation that governs the use of Spanish in the two communities and the teaching of Spanish both in compulsory education (primary and secondary) and university-level education.