Diether of Nassau, German: Diether von Nassau was a clergyman from the Walramian branch of the House of Nassau. From 1300 to 1307 he was Archbishop and Elector of Trier as Diether III.

Baldwin of Luxembourg was the archbishop and elector of Trier and archchancellor of Burgundy from 1307 to his death. From 1328 to 1336, he was the administrator of the archdiocese of Mainz and from 1331 to 1337 of the dioceses of Worms and Speyer. He was one of the most prominent German prelates and statesmen of his age, and the most effective ruler of Trier during the late Middle Ages.