- May 18 Omar Khayyám, Persian mathematician (cubic equations), astronomer (Jalali calendar, basis of the Persian calendar), poet (quatrains), and philosopher, born in Nishapur, Khorasan (now Iran) (d. 1131)
- May 25 Emperor Shenzong of China, 6th emperor of the Song dynasty in China, born in Kaifeng, China (d. 1085)
Greatest Generation
Silent Generation
Baby Boomer
Generation X
Millennial
Generation Z