Æthelred I (disambiguation)

Æthelred I or Ethelred I may refer to:


 * Æthelred I of Wessex, King of Wessex from 865 to 871
 * Æthelred I of Northumbria, King of Northumbria from 774 to 779 and again from 788 or 789 until his murder in 796
 * Æthelred I of East Anglia, King of East Anglia