| Type: | Bishop |
| Honorific Prefix: | The Most Reverend |
| Johannes IX Tiedemann | |
| Prince-Bishop of Lübeck | |
| Church: | Roman Catholic |
| Diocese: | Diocese of Lübeck |
| Death Date: | 17 April 1561 |
| Death Place: | Bremen |
| Birth Place: | Stadthagen |
| Predecessor: | Andreas von Barby |
| Successor: | Eberhard von Holle |
| Elected: | 11 August 1559 |
| Term End: | 17 April 1561 |
Johannes Tiedemann (– 17 April 1561) known as Johannes IX, was the last Catholic Prince-Bishop of Lübeck.
Johann Tiedemann was born around 1503 in Stadthagen, a son of Hans Tiedemann and his wife Geseke and brother of Christoph Tiedemann. His mother was a sister of the Lübeck council secretary and cathedral dean Johannes Rode, who also came from Stadthagen. In 1528 Tiedemann received a prebend at Lübeck Cathedral. In 1544 he was appointed Vice Dean of the absent Dean Johannes von Weeze. After his death in 1548 he was elected cathedral dean by the cathedral chapter and in the same year appointed vicar general for the absent bishop Theodor von Rheden. On 11 August 1559, the chapter elected him to succeed Andreas von Barby as Bishop of Lübeck. He received papal confirmation on 20 February 1561, but died shortly thereafter.
His double epitaph together with his brother, the canons in Lübeck and Ratzeburg Christoph Tiedemann († 1561), with a Latin inscription is in the ambulatory of Lübeck Cathedral.[1] His monumental bronze tombstone in the Renaissance style is also in the cathedral, formerly in the choir, since the end of the 19th century on the south wall in the south aisle. It shows him in full pontifical vestments, albeit not yet consecrated with the mitre in hand, and was made in 1563 by the Lübeck council founder Matthias Benningk. It is the only surviving Renaissance grave slab of this type and size in Lübeck.[2]