The East Slavs are Slavic peoples speaking East Slavic languages. Formerly the main population of the medieval state of Kievan Rus, by the seventeenth century they evolved into the Russian, Ukrainian, and Belarusian peoples.

Relatively little is known about the Eastern Slavs prior to approximately 859 AD, the date from which the account in the Primary Chronicle starts. The reasons are the apparent absence of a written language (Cyrillic script, created about 863 was specifically for Slavic adoption) and the remoteness of East Slavic lands. What little is known comes from archaeological digs, foreign traveller accounts of the Rus land, and linguistic comparative analyses of Slavic languages.

Very few native Rus' documents dating before the 11th century (none ante-dating the 10th century) have been discovered. The earliest major manuscript with information on Rus' history is the Primary Chronicle, written in the late 11th and early 12th centuries. It lists the twelve Slavic tribal unions who, by the 9th century settled between the Baltic Sea and the Black Sea. These tribal unions were Polans, Drevlyans, Dregovichs, Radimichs, Vyatichs, Krivichs, Slovens, Dulebes (later known as Volhynians and Buzhans), White Croats, Severians, Ulichs, Tivertsi.

The Slavic peoples are an Indo-European panethnicity living in Central Europe, Eastern Europe, Southeast Europe, North Asia and Central Asia. The term Slavic represents a broad ethno-linguistic group of people, who speak languages belonging to the Slavic language family and share, to varying degrees, certain cultural traits and historical backgrounds. From the early 6th century they spread to inhabit most of Central and Eastern Europe and the Balkans. In addition to their main population centre in Europe, some East Slavs (Russians) also settled later in Siberia and Central Asia. Part of all Slavic ethnicities emigrated to other parts of the world. Over half of Europe's territory is inhabited by Slavic-speaking communities. The worldwide population of people of Slavic descent is close to 400 million for which they rank fourth among panethnicities in the world.

Modern nations and ethnic groups called by the ethnonym Slavs are considerably diverse both in appearance and culturally, and relations between them – even within the individual ethnic groups themselves – are varied, ranging from a sense of connection to feelings of mutual hostility.

East Slavic can refer to: