This chapter outlines of the main patterns of spatial variation in contemporary Galician at the phonological, morphosyntactic and lexical levels. The first two sections discuss some aspects linked to the history of the study of Galician dialects and the dialectal documentation work carried out in the last century. The following section presents a list of phonetic, morphosyntactic and lexical variables within the Galician linguistic domain. This is followed by a characterisation of the main dialectal varieties based on the classification propositions made in recent years. The contribution concludes with an exposition on the relationship between dialects and standard language, on the vitality of dialectal varieties at present and the study of linguistic changes in these varieties.