Ghiyās o-Dīn Abol-Fath Omār ibn Ebrāhīm Khayyām Neyshābūri (Persian: غیاث الدین ابو الفتح عمر بن ابراهیم خیام نیشابوری) (born Neyshābūr, Persia, May 18, 1048 – died December 4, 1122) was a Persian poet, mathematician, philosopher and astronomer who lived in Persia. His name is also given as Omar al-Khayyami.