Yaropolk I Sviatoslavich (c. 958–960 – 11 June? 980) (East Slavic: Ярополк I Святославич, sometimes transliterated as Iaropolk) was a young and rather enigmatic ruler of Kiev between 972 and 980. He was the oldest son of Svyatoslav. His royal title is traditionally translated as "Prince".

Yaropolk was given Kiev by his father Sviatoslav I, who left on a military campaign against the Danube Bulgars. Soon after Svyatoslav's death, however, civil war began between Yaropolk and his brothers. According to one chronicle, Yaropolk's brother Oleg killed Lyut, the son of Yaropolk's chief adviser and military commander Sveneld. In an act of revenge and at the insistence of Sveneld, Yaropolk went to war against his brother and killed him. Then, Yaropolk sent his men to Novgorod, from which his other brother Vladimir had fled on receiving the news about Oleg's death. Yaropolk became the sole ruler of Rus'.

In 980, Vladimir returned with the Varangian mercenaries and attacked Yaropolk. On his way to Kiev, Vladimir seized Polotsk because Rogneda, daughter of the Polotsk prince Rogvolod, had chosen Yaropolk over him. Vladimir forced Rogneda to marry him. Then, Vladimir seized Kiev with the assistance from a boyar Blud, who had become Yaropolk's chief adviser upon the death of Sveneld. Blud betrayed Yaropolk by advising him to flee from Kiev and go into retreat in the town of Rodnya at the mouth of the Ros' River. Vladimir besieged Rodnya and starved Yaropolk into negotiations. Yaropolk trusted Blud and his brother's promises of peace and left for Vladimir's headquarters, where he would be killed in an ambush by two Varangians.

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