Sayf ad-Din Yalbugha ibn Abdullah al-Umari an-Nasiri al-Khassaki, better known as Yalbugha al-Umari or Yalbugha al-Khassaki, was a senior Mamluk emir during the Bahri period. Originally a mamluk of Sultan an-Nasir Hasan (r. 1347–1351, 1354–1361), he rose through the ranks as the senior emirs Shaykhu and Sirghitmish were eliminated, becoming the amir majlis (lord of the audience, a senior administrative official), and achieving the highest military rank of amir mi'a muqaddam alf (emir of 100 mounted horsemen and commander of 1,000 soldiers). Ties between Yalbugha and an-Nasir Hasan deteriorated and the former had the latter, his master, killed in a violent power struggle in 1361.