Æthelhelm or Æþelhelm ( - ) was the elder of two known sons of Æthelred I, King of Wessex from 865 to 871, and Queen Wulfthryth.

Æthelred's sons were infants when their father died in 871, and the throne passed to their uncle, Alfred the Great. The only certain record of Æthelhelm is as a beneficiary in Alfred's will in the mid 880s, and he probably died at