The Wheel of Mainz or Mainzer Rad, in German, was the coat of arms of the Archbishopric of Mainz and thus also of the Electorate of Mainz (Kurmainz), in Rhineland-Palatinate, Germany. It consists of a silver wheel with six spokes on a red background. The wheel can also be found in stonemasons' carvings and similar objects. Currently, the City of Mainz uses a double wheel connected by a silver cross.

Willigis was Archbishop of Mainz from 975 until his death as well as archchancellor of the Holy Roman Empire.