This paper explores the contexts of emergence and application of Cognitive Sociolinguistics. This novel field of scientific enquiry draws on the convergence of methods and theoretical frameworks typically associated with Cognitive Linguistics and Sociolinguistics. The paper traces and systematizes the key theoretical and epistemological bases for the emergence of Cognitive Sociolinguistics, by outlining main research strands and highlighting some challenges that face the development of this field. More specifically, it focuses on the following terms and concepts which are foundational to the discussion of Cognitive Sociolinguistics: (i) usage-based linguistics and language-internal variation; (ii) rule-based vs. usage-based conceptions of language; (iii) meaning variation; (iv) categorization and prototypes; and (v) the interplay between language, culture, and ideology. Finally, it considers the benefits of taking a Cognitive Sociolinguistic perspective in research by looking at the actual studies that are presented in the current volume.