The Yotvingian lived in the area of Sudovia (Yotvingia) and Dainava, southwest from the upper Neman (Nemunas). Today this area corresponds mostly to the Podlaskie Voivodeship of Poland, portions of Lithuania and a part of Hrodna Province of Belarus. The territory was between later the Marijampolė and Merkinė (Lithuania); Slonim and Kobryn (Belarus); and Białystok, and Lyck, now Ełk (Poland).
The name Sūduva, according to Vytautas Mažiulis ("Prūsų kalbos etimologijos žodynas", Etymological Dictionary of the Prussian Language), derives from a local hydronym *Sūd(a)vā, in turn derived from a Baltic verbal root *sū-: to flow, pour.
A. S. Kibin proposed Yotvingian, or the "Slavic Jatviagi as the group name goes back to O. N. patronymic derivative játvingar meaning « the descendants of Játvígr », or « the people of Játvígr »" - "the name Játvígr mentioned by Knytlinga saga". J. Pashka, acknowledging Kibin's proposal, has similarly interpreted the ethnonym as derived from the Old Norse Játvígr, with a genitive Játvígs liðsmenn ( ᛃᚨᛏᚢᛁᚴᛋ ᚱᛟᚦᛋ ) label of Játvígr's Viking expedition and his Norse Rus' settlers ( i.e. Indura, Belarus ) by the Nemunas river. Pashka asserts the nasal infixation in the original Old Norse Játvíg name of the 944-945 Kiev Treaty was probably an insignificant scribal error or misinterpretation, that has survived to the present.
According to The Histories of Herodotus (5th century B.C.), the Neuri Νέυροι were a tribe living beyond the Scythian cultivators, one of the nations along the course of the river Hypanis (Bug river), west of the Borysthenes (Dniepr river). This was roughly the area of modern Belarus and Eastern Poland by the Narew river, coinciding with the Yotvingian linguistic territory of toponyms and hydronyms (Narew river).