Rhein-Selz is a Verbandsgemeinde ("collective municipality") in the district Mainz-Bingen in Rhineland-Palatinate, Germany. It takes its name from the two rivers Rhine and Selz. It is situated on the left bank of the Rhine, south of Mainz. It was formed on 1 July 2014 by the merger of the former Verbandsgemeinden Nierstein-Oppenheim and Guntersblum. Its seat is in Oppenheim.

The Verbandsgemeinde consists of the following Ortsgemeinden ("local municipalities"):

Dalheim Dexheim Dienheim Dolgesheim Dorn-Dürkheim Eimsheim Friesenheim Guntersblum Hahnheim Hillesheim

Köngernheim Ludwigshöhe Mommenheim Nierstein Oppenheim Selzen Uelversheim Undenheim Weinolsheim Wintersheim

49°50′N 8°18′E / 49.84°N 8.30°E / 49.84; 8.30