Sviatoslav Olgovich[a] (died February 14, 1164) was Prince of Novgorod (1136–1138); Novgorod-Seversk (1139); Belgorod (1141–1154); and Chernigov (1154–1164).

With the assistance of his ally, Yuri Dolgoruki, and his father-in-law, Aepa Khan, Sviatoslav began a war against his cousins, but was forced to flee to Karachev.

Upon his death in 1164, his widow Catherine briefly ruled as princess regnant of Chernigov.

[3] The reign of Ekaterina or Catherine of Chernigov lasted for a few days, during which she kept her husband's death a secret while she summoned her (step-?

)son Oleg to come to Chernigov quickly, and told the city's leading men not inform her brother-in-law Sviatoslav Vsevolodich, who was the rightful heir to the Chernigovian throne.