Dęblin is a town at the confluence of Vistula and Wieprz rivers, in Lublin Voivodeship, Poland. Dęblin is the part of the agglomeration with adjacent towns of Ryki and Puławy, which altogether has over 100 000 inhabitants. The population of the town itself is 15,505. Dęblin is part of the historic region of Lesser Poland. Since 1927 it has been the home of the chief Polish Air Force Academy, and as such Dęblin is one of the most important places associated with aviation in Poland. The town is also a key railroad junction, located along the major Berlin – Warsaw line, with two additional connections stemming from Dęblin – one westwards to Radom, and another one northeast to Łuków.

The Vistula is the longest river in Poland and the ninth-longest in Europe, at 1,047 kilometres in length. Its drainage basin, extending into three other countries apart from Poland, covers 193,960 km2 (74,890 sq mi), of which 168,868 km2 (65,200 sq mi) is in Poland.