Esen (1407–1454), was a powerful Oirat taishi and the de facto ruler of the Northern Yuan dynasty between 12 September 1453 and 1454. He is best known for capturing the Emperor Yingzong of Ming in 1449 in the Battle of Tumu Fortress and briefly reuniting the Mongol tribes. The Four Oirat reached the peak of their power under his rule.

Oirats or Oirds, also formerly Eluts and Eleuths, are the westernmost group of the Mongols whose ancestral home is in the Altai region of Siberia, Xinjiang and western Mongolia.