Silesians (Silesian: Ślōnzŏki or Ślůnzoki; Silesian German: Schläsinger or Schläsier; German: Schlesier pronounced [ˈʃleːzi̯ɐ] ; Polish: Ślązacy; Czech: Slezané) is both a linguistic as well as a geographical term for the inhabitants of Silesia, a historical region in Central Europe divided by the current national boundaries of Poland, Germany, and Czechia. Historically, the region of Silesia (Lower and Upper) has been inhabited by Polish (West Slavic Lechitic people), Czechs, and Germans. Therefore, the term Silesian can refer to anyone of these ethnic groups. However, in 1945, great demographic changes occurred in the region as a result of the Potsdam Agreement leaving most of the region ethnically Polish and/or Slavic Upper Silesian. The names of Silesia in different languages most likely share their etymology—Polish: ; German: Schlesien pronounced [ˈʃleːzi̯ən] ; Czech: Slezsko [ˈslɛsko]; Lower Silesian: Schläsing; Silesian: Ślōnsk [ɕlonsk]; Lower Sorbian: Šlazyńska [ˈʃlazɨnʲska]; Upper Sorbian: Šleska [ˈʃlɛska]; Latin, Spanish and English: Silesia; French: Silésie; Dutch: Silezië; Italian: Slesia; Slovak: Sliezsko; Kashubian: Sląsk. The names all relate to the name of a river (now Ślęza) and mountain (Mount Ślęża) in mid-southern Silesia, which served as a place of cult for pagans before Christianization.
Ślęża is listed as one of the numerous Pre-Indo-European topographic names in the region (see old European hydronymy). According to some Polonists, the name Ślęża [ˈɕlɛ̃ʐa] or Ślęż [ɕlɛ̃ʂ] is directly related to the Old Polish words ślęg [ɕlɛŋk] or śląg [ɕlɔŋk], which means dampness, moisture, or humidity. They disagree with the hypothesis of an origin for the name Śląsk [ɕlɔ̃sk] from the name of the Silings tribe, an etymology preferred by some German authors.