| Constantine Ypsilantis | |
| Succession: | Prince of Moldavia |
| Reign1: | 9 March 1799 – 4 July 1801 |
| Predecessor1: | Alexandru Callimachi |
| Successor1: | Alexandros Soutzos |
| Succession2: | Prince of Wallachia (1st reign) |
| Reign2: | 1 September 1802 – August 1806 |
| Predecessor2: | Alexandros Soutzos |
| Successor2: | John Caradja |
| Succession3: | Prince of Wallachia (2nd reign) |
| Reign3: | 27 December 1806 – 31 May 1807 |
| Predecessor3: | Alexandros Soutzos |
| Successor3: | Russian occupation |
| Spouse: | Ralu Callimachi |
| Issue: | Alexander Ypsilantis Demetrios Ypsilantis Eleni Ypsilanti Nikolaos Ypsilantis Georgios Ypsilantis Grigorios Ypsilantis Ekaterini Ypsilanti Maria Ypsilanti |
| House-Type: | Dynasty |
| Father: | Alexander Ypsilantis |
| Birth Date: | 1760 |
| Birth Place: | Constantinople, Ottoman Empire (modern-day Istanbul, Turkey) |
| Death Date: | 24 June 1816 |
| Death Place: | Kyiv, Russian Empire (modern-day Ukraine) |
| Religion: | Orthodox |
Constantine Ypsilantis (Greek, Modern (1453-);: Κωνσταντίνος Υψηλάντης Konstantinos Ypsilantis; Romanian; Moldavian; Moldovan: Constantin Ipsilanti; 1760 - 24 June 1816) was the son of Alexander Ypsilantis, a key member of an important Phanariote family, Grand Dragoman of the Porte (1796–1799), hospodar[1] of Moldavia (1799–1802) and Walachia (1802–1806), and a Prince[2] through marriage to the daughter of Alexandru Callimachi.
Ypsilantis had joined in a conspiracy to liberate Greece and, on its discovery, fled to Vienna, had been pardoned by the sultan and in 1799 appointed by him hospodar of Moldavia. Deposed in 1805, he escaped to St Petersburg, and in 1806, at the head of some 20,000 Russians, returned to Bucharest, where he set to work on a fresh attempt to liberate Greece.
From 1806, during Russian occupation of the Principalities of Moldavia and Wallachia, Russia encouraged their provisional union under Prince Constantine Ypsilanti. Russia preferred their union for improved relations with the Principalities and their formal union was planned for 1830.
Ypsilantis' plans were ruined by the Peace of Tilsit and in 1807 he emigrated with his family to Russia.
Ypsilantis died, in Kyiv, where he had served as commandant of the Pechersk Fortress since 1807. He left five sons, of whom two played a conspicuous part in the Greek War of Independence: Alexander and Demetrios.