The Transylvanian Saxons (Siebenbürger Sachsen; Transylvanian Saxon: Siweberjer Såksen or simply Soxen, singularly Sox or Soax; Transylvanian Landler: Soxn or Soxisch; Sași ardeleni, sași transilvăneni/transilvani; erdélyi szászok) are a people of mainly German ethnicity and overall Germanic origin; mostly Luxembourgish initially during the medieval Ostsiedlung process, then also from other parts of present-day Germany) who settled in Transylvania (Transilvania or Ardeal, Hungarian: Erdély, Siebenbürgen or Transsilvanien, historically also Überwald, Transsilvania, Septem Castra or Septem Castrensis, Medieval Latin: Trānsylvānia) in various waves, starting from the mid and mid-late 12th century until the mid 19th century.
The first ancestors of the Transylvanian 'Saxons' originally stemmed from Flanders, Hainaut, Brabant, Liège, Zeeland, Moselle, Lorraine, and Luxembourg, then situated in the north-western territories of the Holy Roman Empire around the 1140s and 1150s.
Alongside the Baltic Germans from Estonia and Latvia and the Zipser Germans (also sometimes known or referred to as Zipser Saxons) from Zips, northeastern Slovakia, as well as Maramureș and Bucovina, the Transylvanian Saxons are one of the three oldest German-speaking and ethnic German groups of the German diaspora in Central-Eastern Europe, having continuously been living there since the High Middle Ages onwards. The Transylvanian Saxons are part of the broader/larger group of Romanian Germans (Rumäniendeutsche, Germanii din România) as well, being the eldest and one of the most important of all the constituent sub-groups of this ethnic community.
Their native dialect, Transylvanian Saxon (endonym: Siweberjesch Såksesch, Siebenbürgisch-Sächsisch, Dialectul săsesc, limba săsească, or săsește) is close to Luxembourgish. Nowadays, organisations representing the Transylvanian Saxons exist in Romania, Germany, Austria, Canada, and the United States (in the latter case most notably 'Alliance of Transylvanian Saxons').