Swedish is a North Germanic language spoken predominantly in Sweden and in parts of Finland. It has at least 10 million native speakers, the fourth most spoken Germanic language and the first among any other of its type in the Nordic countries overall.

Swedish, like the other Nordic languages, is a descendant of Old Norse, the common language of the Germanic peoples living in Scandinavia during the Viking Era. It is largely mutually intelligible with Norwegian and Danish, although the degree of mutual intelligibility is largely dependent on the dialect and accent of the speaker. Written Norwegian and Danish are usually more easily understood by Swedish speakers than the spoken languages, due to the differences in tone, accent, and intonation.
Standard Swedish, spoken by most Swedes, is the national language that evolved from the Central Swedish dialects in the 19th century and was well established by the beginning of the 20th century. While distinct regional varieties and rural dialects still exist, the written language is uniform and standardized. Swedish is the most widely spoken second language in Finland where it has status as co-official language.

Swedish was long spoken in parts of Estonia, although the current status of the Estonian Swedish speakers is almost extinct. It is also used in the Swedish diaspora, most notably in Oslo, Norway, with more than 50,000 Swedish residents.