Dubysa, at 131km, is the 15th longest river solely in Lithuania. It originates just a few kilometers from Lake Rėkyva near Šiauliai city. At first it flows south, but at Lyduvėnai turns southeast and near Ariogala - southwest. Dubysa is a Samogitian river. The first few kilometres of Dybysa are also known as Genupis or Šventupis.