Mongol Armenia or Ilkhanid Armenia refers to the period beginning in the early-to-mid 13th century during which both Zakarid Armenia and the Armenian Kingdom of Cilicia became tributary and vassal to the Mongol Empire and the successor Ilkhanate. Armenia and Cilicia remained under Mongol influence until around 1335.

During the time period of the later Crusades (1250s to 1260s), there was a short-lived Armenian-Mongol alliance, engaged in some combined military operations against their common enemy, the Mamluks. They succeeded in the Siege of Baghdad, but suffered defeat eight years later.

The Armenian calls for a wider Christian-Mongol alliance against Mamluk Islam, advocated notably by Hayton of Corycus, were ignored by the Latin powers in the Levant, leading to the demise of the European Crusader States and the imminent failure of the Crusades as a whole.

The Armenian Kingdom of Cilicia, or "Lesser Armenia" was formed in the late 11th century, by refugees and migrants from "Greater Armenia". The area was staunchly Christian, as Armenia itself had been the first nation to ever adopt Christianity as its official religion, in the 4th century. Armenians were therefore very friendly to the European Crusaders who began to arrive in the early 12th century. As the Crusades progressed, the Armenian leaders were regular players in the politics of the region, aligning with the Crusader states against the Muslims.

Genghis Khan had died in 1227, and by 1241, the Empire was split up into four smaller independent khanates, which continued to further expand the Empire. The southwestern khanate, known as the Ilkhanate, under the leadership of Genghis Khan's grandson Hulagu, advanced towards Persia and the Holy Land. City after city fell to the Mongols, including some Christian realms in their path. Christian Georgia was repeatedly attacked starting in 1220, and in 1243 Queen Rusudan formally submitted to the Mongols, turning Georgia into a vassal state which then became a regular ally in the Mongol military conquests. This was a common practice in use by the growing Mongol empire – as they conquered new territories, they would absorb the populace and warriors into their own Mongol army, which they would then use to further expand the Empire.

When the Mongols reached the Caucasus, they conquered Greater Armenia/Bagratid Armenia and various Armenian barons opted to swear loyalty to the Mongol Empire. In 1236, the Grand Prince of Karabagh, Hasan Jalal submitted to the Mongols, and in return received back some of the territories which had previously been conquered. He also traveled twice to the Mongol capital of Karakorum, where he negotiated further details of the relationship with the khan.

In the 1240s, as the Mongols continued their advance towards Cilicia, King Hethum I chose to follow the example of the Greater Armenian barons such as Hasan Jalal, and also submitted to the Ilkhanate.

To formalize his own relationship with the Mongols, in 1247 Hethum I sent his elder half-brother Sempad the Constable to the Mongol court in Karakorum. Sempad met with Güyük Khan and his successor, Kublai Khan's brother Möngke Khan, and made an agreement of cooperation, against their common enemy the Muslims. The nature of this relationship is disputed by historians, some of whom call it an alliance, and others who say that the Armenians had submitted to Mongol overlordship, and become a vassal state similar to any other conquered region.