Jewish communities first arrived in Ukraine in the 10th century, and by the 11th century comprised 5% of the world Jewish population. They showed complete conformity with all known Jewish communities at the time.

Jewish communities have existed in the territory of Ukraine from the time of Kievan Rus' (late 9th to mid-13th century)[9][10] and developed many of the most distinctive modern Jewish theological and cultural traditions such as Hasidism.[citation needed] According to the World Jewish Congress, the Jewish community in Ukraine constitute the third-largest Jewish community in Europe and the fifth-largest in the world.[3]

While at times it flourished, at other times the Jewish community faced periods of persecution and antisemitic discriminatory policies.[citation needed] In the Ukrainian People's Republic, Yiddish was a state language along with Ukrainian and Russian. At that time there was created the Jewish National Union and the community was granted an autonomous status.[11] Yiddish was used on Ukrainian currency in 1917–1920.[12] Before World War II, a little under one-third of Ukraine's urban population consisted of Jews[13] who were the largest national minority in Ukraine.[citation needed] Ukrainian Jews are comprised by a number of sub-groups, including Ashkenazi Jews, Mountain Jews, Bukharan Jews, Crimean Karaites, Krymchak Jews and Georgian Jews.

In the westernmost area of Ukraine, Jews were mentioned for the first time in 1030.https://en.wikipedia.org/wiki/History_of_the_Jews_in_Ukraine

also

Kievan Rus'
Main article: Kievan Rus
By the 11th century, Byzantine Jews of Constantinople had familial, cultural, and theological ties with the Jews of Kiev. For instance, some 11th-century Jews from Kievan Rus participated in an anti-Karaite assembly held in either Thessaloniki or Constantinople.[24] One of the three Kievan city gates in the times of Yaroslav the Wise was called Zhydovski (Judaic).

Galicia-Volhynia
Main articles: Kingdom of Galicia–Volhynia and Shtetl In Halychyna (Galicia), the westernmost area of Ukraine, Jews were mentioned for the first time in 1030. From the second part of the 14th century, they were subjects of the Polish kings, and magnates. The Jewish population of Halychyna and Bukovyna, part of Austria-Hungary, was extremely large; it made up 5% of the global Jewish population.https://en.wikipedia.org/wiki/History_of_the_Jews_in_Ukraine