The population of Armenia is 3,336,100 (2001 estimate), giving the country’s land area a population density of 112 persons per sq km (290 per sq mi). Armenia is highly urbanized, with 70 percent of all residents living in cities or towns. Population is concentrated in river valleys, especially along the Hrazdan River, where Yerevan, the capital and largest city, is located. Armenia’s second-largest city is Gyumri (formerly Leninakan), the site of a devastating earthquake in 1988.

Armenians constitute nearly all of the country's population; they speak Armenian, a distinct branch of the Indo-European language family. The remainder include Kurds, Russians, and small numbers of Ukrainians, Assyrians, and other groups. Most of Armenia's Azerbaijani population fled or was expelled after the escalation of the conflict between the two countries. More than 3 million Armenians live abroad, including about 1.5 million in the states of the former Soviet Union and about 1 million in the United States. The Armenians were converted to Christianity about AD 300 and have an ancient and rich liturgical and Christian literary tradition. Believing Armenians today belong mainly to the Armenian Apostolic (Orthodox) church or the Armenian Catholic church, in communion with Rome.