| Duke of Saxe-Zeitz-Pegau-Neustadt | |
| Friedrich Heinrich | |
| Full Name: | German: Friedrich Heinrich |
| Spouse: | Sophie Angelika of Württemberg-Oels Anna Fredericka Philippine of Schleswig-Holstein-Sonderburg-Wiesenburg |
| Issue: | Maurice Adolf Karl Dorothea Charlotte |
| House: | Wettin |
| Father: | Maurice, Duke of Saxe-Zeitz |
| Mother: | Dorothea Maria of Saxe-Weimar |
| Birth Date: | 21 July 1668 |
| Birth Place: | Moritzburg |
| Death Place: | Neustadt an der Orla |
Frederick Heinrich of Saxe-Zeitz-Pegau-Neustadt (21 July 1668 in Moritzburg – 18 December 1713 in Neustadt an der Orla), was a German prince of the House of Wettin.
He was the fourth (but third surviving) son of Maurice, Duke of Saxe-Zeitz, and his second wife, Dorothea Maria of Saxe-Weimar.
In Öls on 23 April 1699, Frederick Henry married Sophie Angelika of Württemberg-Oels. Shortly after, his older brother, Duke Moritz Wilhelm, Duke of Saxe-Zeitz, gave him the towns of Pegau and Neustadt as appanage. From then on, he assumed the title duke of Saxe-Zeitz-Pegau-Neustadt (Herzog von Sachsen-Zeitz-Pegau-Neustadt). His wife Sophie died after only nineteen months of marriage on 11 November 1700.
In Moritzburg on 27 February 1702, Frederick married for a second time to Anna Fredericka Philippine of Schleswig-Holstein-Sonderburg-Wiesenburg. They had two children:
The death of his nephew, the Hereditary Duke Frederick August, on 17 February 1710, made him the heir apparent of the duchy of Saxe-Zeitz, because his immediate older brother Christian August was a priest.
Nevertheless, he died three years later, five before his brother Maurice Wilhelm. His only son, Maurice Adolf Karl, succeeded him in Pegau-Neustadt, but, still a minor, he was placed under the custody of his uncle Maurice Wilhelm and became the new heir apparent of Saxe-Zeitz. However, soon afterwards (1718) the young Maurice Adolf himself became a priest and renounced his claims to the duchy, which made the extinction of the Saxe-Zeitz line inevitable.
Without other male heirs, Zeitz was finally merged into the Electorate of Saxony after the death of Maurice Wilhelm.