Rhein-Neckar-Kreis is a district (Kreis) in the northwest of Baden-Württemberg, Germany. Neighboring districts are Bergstraße, Odenwaldkreis, Neckar-Odenwald, Heilbronn, Karlsruhe, the free district of Speyer, the Rhein-Pfalz-Kreis, and the municipalities of Mannheim and Heidelberg.