Mayen-Koblenz is a district (Kreis) in the north of Rhineland-Palatinate, Germany.

Neighboring districts are (from north clockwise) Ahrweiler, Neuwied, Westerwaldkreis, district-free Koblenz, Rhein-Lahn, Rhein-Hunsrück, Cochem-Zell, and Vulkaneifel.

The two main rivers of the district are the Rhine and the Moselle, which join at the Deutsches Eck in Koblenz.

These also include the large lake, the Laacher See, a volcanic caldera formed 12000 years ago.

The crown is a reference to the fact that in Rhens the Councils of Electors took place to choose the emperors and kings of the Holy Roman Empire.