Alkmund of Derby (or of Lilleshall), also spelt Ealhmund, Alhmund, Alcmund, or Alchmund (d. c. 800) was a son of Alhred of Northumbria. After more than twenty years in exile as a result of Northumbrian dynastic struggles, he returned with an army. He was killed in about 800, for which King Eardwulf of Northumbria was held responsible. Whatever the exact circumstances, his death was regarded as a martyrdom, and Alkmund as a saint.
Alkmund was buried at Derby, where miracles were reported at the tomb. In the early tenth century, his remains were translated to Shrewsbury, probably by Æthelflæd, Lady of the Mercians.
When St Alkmund's, Shrewsbury became the property of Lilleshall Abbey about 1145, his body was probably translated back to Derby. Confusion about his first place of burial has arisen from this connection to Lilleshall.
When St Alkmund's Church, Derby was demolished in 1968, several earlier churches were revealed, stretching back to the 9th century. Artefacts found included the stone sarcophagus.
Six churches in England are dedicated to him, at Derby, Duffield, Shrewsbury, Whitchurch (Shropshire), Aymestrey and Blyborough.
His feast day is 19 March.