Eastern Armenia ( Arevelyan Hayastan) is a term used by Armenians to refer to the eastern parts of the Armenian Highlands, the traditional homeland of the Armenian people. Between the 4th and the 20th centuries, Armenia was partitioned several times and the terms Eastern and Western Armenia have been used to refer to its respective parts under foreign occupation or control. Although there has not been a defined line between the two. The term has been used to refer to:

• Persian Armenia (a vassal state of the Persian Empire from 387, fully annexed in 428) after the country's partition between the Byzantine and Sassanian empires and lasted until the Arab conquest of Armenia in the mid-7th century. It is also used (more commonly) for the period of Persian-controlled parts of Armenia after the 1555 Peace of Amasya until the area was ceded to Russia in 1828 following the Treaty of Turkmenchay.
• Russian Armenia (1828 to 1917) and Soviet Armenia (1917 to 1991), which covered the Armenian populated areas under the control of the Russian Empire and the Soviet Union, respectively.