| John X of Schleswig-Holstein-Gottorp | |
| Noble Family: | House of Oldenburg |
| Father: | John Adolf, Duke of Holstein-Gottorp |
| Mother: | Augusta of Denmark |
| Spouse: | Julia Felicitas of Württemberg-Weiltingen |
| Birth Date: | 18 March 1606 |
| Birth Place: | Gottorf Castle |
| Death Place: | Eutin |
John of Schleswig-Holstein-Gottorp, nicknamed Bishop Hans called Hans Bishop, (18 March 1606 at Gottorf Castle - 21 February 1655 in Eutin), was a Lutheran Administrator of Prince-Bishopric of Lübeck.
John was the son of the Duke John Adolph of Schleswig-Holstein-Gottorp and the nephew of the previous Administrator John Frederick, whom he succeeded in 1634.
John was the first Administrator of Lübeck to take permanent residence at Eutin Castle, which he kept expanding. He tried to draw scholars and scientists to his court and to promote the economic development of the prince-bishopric, but his efforts were hampered by the outbreak of the plague in the years 1638 and 1639, while at the same time the Thirty Years' War imposed additional burdens on the country. Thus Danish troops were quartered in the capital Eutin both in 1638/1639 and in 1643, and in December 1643 a whole Swedish cavalry regiment was quartered in Eutin. The Prince-Bishopric had to house and feed this regiment.
During the negotiations in Osnabrück that led to the Peace of Westphalia, the existence of his Prince-Bishopric was at risk: the possibility existed that his land would be given to some other state as territorial compensation for an earlier annexation. John managed to avert this danger by carefully selecting his negotiators; first David Gloxin from Lübeck, then his councillor Christian Cassius.
John married on 7 May 1640 to Princess Julia Felicitas (1619-1661), a daughter of Duke Julius Frederick of Württemberg-Weiltingen. The marriage was an extremely unhappy one. John tried to divorce in 1648 and finally succeeded in 1653. The couple had four children: