| Honorific Prefix: | Saint |
| Nemesion | |
| Birth Place: | Egypt |
| Death Date: | 250 |
| Death Place: | Alexandria, Egypt |
| Canonized Date: | Pre-congregation |
| Feast Day: | 19 December or 10 September |
Saint Nemesion (or Nemesian, Nemesius, Nemesis; died 250) was an Egyptian martyr in Alexandria, Egypt during the persecutions of Christians by the Roman emperor Decius.A group of other Christians were martyred at the same time.His feast day is 19 December, or 10 September in some calendars.
The monks of St Augustine's Abbey, Ramsgate wrote in their Book of Saints (1921),
John Gilmary Shea (1824–1892) in his Pictorial Lives of the Saints wrote,
The hagiographer Alban Butler (1710–1773) wrote in his Lives of the Fathers, Martyrs, and Other Principal Saints under December XIX,