Yi or YI may refer to:
Philosophic principle
Yi (philosophy) (义; 義, righteousness, justice) among the Three Fundamental Bonds and Five Constant Virtues
Ethnic groups Dongyi, the Eastern Yi, or Tung-yi (Chinese: , Yí), ancient peoples who lived east of the Zhongguo in ancient China Yi people (Chinese: , Yí; Vietnamese: Lô Lô), an ethnic group in modern China, Vietnam, and Thailand
Language Yi (Cyrillic), the letter of the Ukrainian alphabet written "Ї" and "ї" Yi language or the Nuosu language spoken by the Yi people of China Yi script, either of two scripts used to write the Yi languages Yiddish (ISO 639-1 language code: yi), the historical language of the Ashkenazi Jews Yi, an obsolete Japanese kana
Mythology and religion Yi the Archer or Houyi, a heroic archer and hunter in Chinese mythology Yi (husbandman), also known as Boyi or Bo Yi, a heroic user of fire and government minister in Chinese mythology
People Surname Yi (surname 易) Yi (surname 伊) Yi (Korean surname) (李,이), including House of Yi, household of Joseon and the Korean Empire Yi Sun-sin (1545–1598), Korean admiral
Given name Lu Yi (disambiguation), several persons Wu Yi (politician) (born 1938), Vice Premier of China
Places Yi County (disambiguation), two counties in China Yí River, a river in Uruguay Yi River (Henan), a river in China Serbia and Montenegro (FIPS country code: YI), a country in Southeast Europe
Other uses Yi (dinosaur) Yi (drinkware) (), former name for the zun, a traditional bronze drinkware of ancient China Yi (prefix symbol), the prefix symbol of the binary unit prefix yobi, representing 280, the equivalent of the decimal prefix yotta- (Y) Yi (), an East Asian counting unit meaning 100,000,000 Yi (vessel) (), a different kind of bronze vessel used in traditional rituals in ancient China YI Technology, a Chinese company that manufactures cameras and computer vision technologies I Ching, or Yijing, ancient Chinese text "Yi" and "iMi", songs by American indie folk band Bon Iver Iraq (aircraft registration prefix YI)
See also Yii Yi Prefecture (disambiguation) Yee (disambiguation)