| Tuman bay I | |
| Succession: | Sultan of Egypt and Syria |
| Reign: | 25 January – 20 April 1501 |
| Predecessor: | Abu al-Nasir Janbalat |
| Successor: | Al-Ashraf Qansuh Al-Ghuri |
| Spouse: | Khawand Fatima[1] |
| Birth Date: | Around 1461 |
| Death Date: | After 1501 |
| Religion: | Sunni Islam |
Al-Adil Sayf ad-Din Tuman bay (Arabic: السلطان الملك العادل أبو النصر طومان باى الأشرفى قايتباى) was the twenty fifth Mamluk Sultan of Egypt from the Burji dynasty. He ruled for about one hundred days in 1501.
Tuman Bay I was about forty years old when he was selected as Sultan.[2] Although he was popular before becoming a Sultan, he soon lost that popularity due to his cruel measures, which was manifested in condemning one of the princes to death by hanging for alleged conspiracy.
He was overthrown and succeeded by Al-Ashraf Qansuh al-Ghawri.