Boris Vyacheslavich () (c. 1053 – October 3, 1078) was a prince of Tmutarakan, son of Vyacheslav Yaroslavich (prince of Smolensk). Boris was izgoi from the Rurikid dynasty of Kievan Rus’. Upon the death of Svyatoslav Yaroslavich in 1077, his brothers Vsevolod Yaroslavich and Izyaslav Yaroslavich started a bitter rivalry over the Kievan throne. Vsevolod left Chernigov and headed towards Izyaslav, who had set out on a military campaign against Kiev. Boris Vyacheslavich took advantage of his uncle's absence and seized control of Chernigov. He only managed to remain in power for 8 days and then had to flee to Tmutarakan upon hearing the news of Vsevolod's return. In Tmutarakan, Boris was accepted by Roman Svyatoslavich. The two were soon joined by Oleg Svyatoslavich, the second son of Svyatosl