Suvalkija or Sudovia (Lithuanian: Sūduva or Suvalkija or Užnemunė, Polish: Suwalszczyzna) is the smallest of the five cultural regions of Lithuania. Its unofficial capital is Marijampolė. People from Suvalkija are called suvalkiečiai (plural) or suvalkietis (singular). It is located south of the Neman River, in the former territory of Vilkaviškis bishopric. Historically, it is the newest ethnographic region as its most distinct characteristics and separate identity formed during the 19th century when the territory was part of Congress Poland. It was never a separate political entity and even today it has no official status in the administrative division of Lithuania. However, it continues to be the subject of studies focusing on Lithuanian folk culture of the 19th and early 20th centuries.
Most of Lithuania's cultural differences blended or disappeared during the Soviet era (1944–1990), remaining the longest in southeastern Lithuania. The concept remains popular among Lithuanian people. A 2008 survey of freshmen and sophomores at Kaunas' Vytautas Magnus University found that 80% of the students continued to identify themselves with one of the regions. Efforts are made to preserve, record, and promote any remaining aspects of the original folk culture.