This review provides a state-of-the-art overview of Spanish sociolinguistics and discusses several areas, including variationist sociolinguistics, bilingual and immigrant communities, and linguistic ethnography. We acknowledge many recent advances and the abundant research on several classic topics, such as phonology, morphosyntax, and discourse-pragmatics. We also highlight the need for research on understudied phenomena and emphasize the importance of combining both quantitative and ethnographic methodologies in sociolinguistic research. Much research on Spanish has shown that the language's wide variation across the globe is a reflection of Spanish-speaking communities’ rich sociohistorical and demographic diversity. Yet, there are many areas where research is needed, including bilingualism in indigenous communities, access to bilingual education, attitudes toward speakers of indigenous languages, and language maintenance and attrition. Language policy, ideology, and use in the legal and health care systems have also become important topics of sociolinguistics today as they relate to issues of human rights.