The Rhein-Sieg-Kreis is a Kreis (district) in the south of North Rhine-Westphalia, Germany. Neighboring districts are Rheinisch-Bergischer Kreis, Oberbergischer Kreis, Altenkirchen, Neuwied, Ahrweiler, Euskirchen, Rhein-Erft-Kreis, the urban district of Cologne. The federal city of Bonn is nearly completely surrounded by the district.
The district as known today was created in 1969, during the reorganization of the districts in North Rhine-Westphalia, by merging Sieg District with the District of Bonn (from which Bonn itself was separated in 1887 to become an urban district). Sieg District was created in 1825.
Geographically Rhein-Sieg District covers the valley of the river Sieg and also, since the merger with the District of Bonn, that of the Rhine around Bonn, as well an area in the most easterly part of the Eifel.
Number of 1st and 2nd generation foreigners in Rhein-Sieg-Kreis by top 10 country of origin per 31 December 2007