John II of Nassau-Wiesbaden-Idstein (German: Johann II. von Nassau-Wiesbaden-Idstein) was the Archbishop of Mainz from 1397 until 1419. John was the son of Count Adolph II of Nassau-Wiesbaden-Idstein, and a younger brother of Adolph II of Nassau-Wiesbaden-Idstein, Archbishop of Mainz from 1381 until 1390. After Adolph's death in 1390 it was his intention that John succeed him, but the cathedral chapter instead elected Conrad II of Weinsberg. However after Conrad's death in 1396 John was elected. As Archbishop John engineered the deposition of King Wenceslaus in 1399 and the election of Rupert II of the Palatinate as the new king in 1400.