| Oleg III Svyatoslavich | |
| Succession: | Prince of Chernigov |
| Reign1: | 1201/2–1204 |
| Predecessor1: | Igor Svyatoslavich |
| Successor1: | Vsevolod IV of Kiev |
| House: | Olgovichi |
| Father: | Sviatoslav III of Kiev |
| Mother: | Maria Vasilkovna of Polotsk |
Oleg III Svyatoslavich (c. 1147–1204)[1] was a Kievan Rus' prince. His baptismal name was Feodosy.[1] He was prince of Vshchizh (1166–before 1175),[1] of Novgorod-Seversk (1200–1201),[1] and of Chernigov (1201/1202–1204).[1]
Oleg III married his first wife before 1166. She was a daughter of Prince Andrey Yuryevich of Suzdalia and his Cuman wife and may have been named Euphrosyne.
Oleg's second wife was a daughter of Prince Yuriy Rostislavich of Ryazan and may have been named Euphrosyne.
Oleg had three children: one whose name is unknown (died in 1204), a son named David (died in 1196), and a son named Ingor (died between 1211 and 1223).[1]