| Simeon Olelkovich | |
| Birth Date: | 1420 |
| Birth Place: | Slutsk |
| Death Date: | 1470 (aged 50) |
| Death Place: | Kiev (Kyiv) |
| Place Of Burial: | Kyiv Pechersk Lavra |
| Succession: | Prince of Kiev |
| Reign: | 1454–1470 |
| Predecessor: | Alexander Olelko |
| Successor: | Position abolished |
| House: | Olelkovich |
| House-Type: | Dynasty |
| Father: | Alexander Olelko |
| Spouse: | Maria, daughter of Jonas Goštautas |
| Religion: | Orthodox Christian |
Simeon (Simon) Olelkovich[1] (Belarusian: Сямён Алелькавіч, Ukrainian: Семен Олелькович, Russian: Семён Олелькович, Lithuanian: Simonas Olelkaitis; 1420–1470[2]) was the last Prince of Kiev from 1454 to 1470[3] and the Prince of Slutsk from 1443 to 1455.[4]
A member of the Olelkovich family, he descended from Ruthenianized Eastern Orthodox branch of the Gediminids dynasty and was a great-grandson of Algirdas, the Grand Duke of Lithuania. After his father's death he inherited the Principality of Kiev. He conducted an independent policy, fought with the Crimean Tatars, maintained close ties with the Principality of Moldavia, the Genoese colonies and the Principality of Theodoro in the Crimea. However soon after, the Principality of Theodoro was conquered by the emerging Crimean Khanate.
He married Maria (d. 1501), daughter of Jan Gasztołd, by whom he had three children, (d. 1495), Alexandra, wife of Fedor Ivanovich Borovsky, and Sophia (d. 1483), wife of Mikhail III of Tver, the last Prince of Tver.[5]
After the death of Simon Olelkovich, the Principality of Kiev was transformed into the Kiev Voivodeship. His son received the Principality of Pinsk as compensation, but he died young and was succeeded first by his mother, Maria, and then by his brother-in-law, Fedor, after her death. None of his children had any issue.[6]