The Kingdom of Armenia, also the Kingdom of Greater Armenia, or simply Greater Armenia (Armenian: Մեծ Հայք Mets Hayk; Latin: Armenia Maior), sometimes referred to as the Armenian Empire, was a monarchy in the Ancient Near East which existed from 321 BC to 428 AD. Its history is divided into successive reigns by three royal dynasties: Orontid (321 BC–200 BC), Artaxiad (189 BC–12 AD) and Arsacid (52–428).

The root of the kingdom lies in one of the satrapies of the Achaemenid Empire of Persia called Armenia (Satrapy of Armenia), which was formed from the territory of the Kingdom of Ararat (860 BC–590 BC) after it was conquered by the Median Empire in 590 BC. The satrapy became a kingdom in 321 BC during the reign of the Orontid dynasty after the conquest of Persia by Alexander the Great, which was then incorporated as one of the Hellenistic kingdoms of the Seleucid Empire.