Ernst von Mengersdorf (1554–1591) was the Prince-Bishop of Bamberg from 1583 to 1591.
Ernst von Mengersdorf was born in Bamberg on October 23, 1554.
He was elected Prince-Bishop of Bamberg on September 2, 1583, with Pope Gregory XIII confirming his appointment on November 21, 1583. He was consecrated as a bishop by Julius Echter von Mespelbrunn, Bishop of Würzburg, on May 20, 1584.
He died on October 21, 1591, and is buried in Michaelsberg Abbey, Bamberg.