Ahmed Tekuder (Тэгүдэр), also known as Sultan Ahmad (reigned 1282-1284) was the sultan of the the Ulus of Ilkhan, son of Hulegu and brother of Abaqa. He was eventually succeeded by Arghun Khan. Tekuder was born Nicholas Tekuder Khan as a Nestorian Christian, however Tekuder later embraced Islam and changed his name to Ahmed Tekuder.
When Tekuder assumed the throne in 1282, he turned the Ilkhan empire into a sultanate. Tekudar zealously propagated his new faith and sternly required his ranking offices to do the same. However his nephew Arghun, the governor of Khorasan, was a Buddhist; and asked Kublai Khan, the Great Khan of the Mongol Empire and the emperor of the Yuan Dynasty, for help. Although, Kublai was angry with the situation, Arghun had to overthrow Tekuder himself.
Tekuder sent friendly letter to Mamluk sultan and wished a peace. His conversion to Islam and good ties with Mamluks were not seen well by Mongol nobles.
When Arghun received no reply, he declared war against Tekuder. Tekuder asked for help from the Mamluk Sultan but the Mamluks did not fully co-operate with Tekuder. Having only a small army, Tekuder was defeated by Arghun's large army, and he was eventually executed on August 10, 1284.