Cissa (Cyssa, or Cysse) is the name of two persons in the early history of Christian Britain:
1. A regulus in the reign of Kentwin, king of the West Saxons (A.D. 676- 685), having authority over what is now Wiltshire and the greater part of Berkshire. He was a benefactor of Abingdon monastery, founded by his nephew Heane, and there he was buried.
2. An anchorite at Croyland, in the earlier part of the 8th century.