Russian is an East Slavic language spoken in the Russian Federation, in countries of the former Soviet Union and in many other countries. It is the most widely spoken Slavic language and one of the five or six most widely spoken languages in the world (after Mandarin, Spanish, English, and Hindi/Urdu, and on a par with Arabic), with over 275 million speakers worldwide, including second language speakers. It ranks in the top ten in terms of numbers of native speakers as well, with estimates varying from 140,000,000 to 170,000,000.

Russian is the official government language of the Russian Federation and one of two official languages of Belarus, Kazakhstan, and the Kyrgyz Republic, as well as one of the six official languages of the United Nations. Significant minorities (and in various regions the majority) of the population speak it at home in Ukraine, Belarus, the Kyrgyz Republic, Kazakhstan, Moldova, Estonia, and Latvia, and it is spoken commonly in various parts of the rest of the former Soviet Union. Emigré communities have brought Russian to cities around the world, especially in Western Europe, North America, and Israel. In Israel, there are over 700,000 Russian speakers and Russian is one of six official court languages in New York. It has also served as the basis for various language mixes and creoles.