Ælle (also Aelle or Ella) is recorded in early sources as the first king of the South Saxons, reigning in what is now called Sussex, England, from 477 to perhaps as late as 514.

According to the Anglo-Saxon Chronicle, Ælle and three of his sons are said to have landed at a place called Cymensora and fought against the local Britons. The chronicle goes on to report a victory in 491, at present day Pevensey, where the battle ended with the Saxons slaughtering their opponents to the last man.

Ælle was the first king recorded by the 8th century chronicler Bede to have held "imperium", or overlordship, over other Anglo-Saxon kingdoms. In the late 9th-century Anglo-Saxon Chronicle (around four hundred years after his time) Ælle is recorded as being the first bretwalda, or "Britain-ruler", though there is no evidence that this was a contemporary title. Ælle's death is not recorded and although he may have been the founder of a South Saxon dynasty, there is no firm evidence linking him with later South Saxon rulers. The 12th-century chronicler Henry of Huntingdon produced an enhanced version of the Anglo-Saxon Chronicle that included 514 as the date of Ælle's death, but this is not secure.