Werner von Falkenstein (c. 1355[citation needed] – 4 October 1418) was a German nobleman who served as Archbishop and Elector of Trier from 1388 until his death in 1418.

On becoming bishop, Falkenstein successfully rejected his relatives claims to the money Kuno had accumulated in Trier, and used it to finance his numerous feuds, which he had with the Lords of Schleiden, Waldeck, Ehrenberg, the Counts Katzenelnbogen at Rheinfels Castle, and the cities of Oberwesel and St. Goar.

A mutual arrangement ended the war, but the status of Wesel as a Free imperial city (Reichsstadt) was not restored.

The country was devastated by the feuds, the state went bankrupt, and Werner III was confronted with a strong opposition in the cathedral chapter of Trier, which, in 1399, requested that Pope Boniface IX appoint a coadjutor at the side of the ailing archbishop, but this did not happen.

In 1402 von Falkenstein had the Wernerseck Castle, named after him, built in Pellenz as a border fortress against the Archbishop of Cologne.