Plegmund (or Plegemund; died 2 August either 914 or 923) was a medieval English Archbishop of Canterbury. He may have been a hermit before he became archbishop in 890. As archbishop, he reorganised the Diocese of Winchester, creating four new sees, and worked with other scholars in translating religious works. He was canonised after his death.
Little is known of the early life of Plegmund except that he was of Mercian descent. A later tradition, dating 300 years after his death, stated that Plegmund lived as a hermit at Plemstall in Cheshire. His reputation as a scholar attracted the attention of King Alfred the Great, who was trying to revive scholarship. Some time before 887, Alfred summoned Plegmund to his court. There he worked with three other scholars, Wærferth, Bishop of Worcester, Æthelstan and Wærwulf in working on translating Pope Gregory the Great's treatise Pastoral Care into Old English.
Plegmund was selected for the see of Canterbury in 890 by King Alfred. Plegmund's election to the Archbishopric of Canterbury is recorded in Manuscript E of the Anglo-Saxon Chronicle: "Here Archbishop Plegmund was elected by God and all the people."Fulk, Archbishop of Reims, praised the election of Plegmund, stating that he would help root out the last remnants of paganism in the people. However, there was a gap in time between the death of the previous Archbishop of Canterbury, Ethelred, and the consecration of Plegmund; this may have been because the see had been offered to Grimbald, a Flemish monk and scholar, who refused it. Plegmund was granted his pallium by Pope Formosus.