Edgar or Étgar mac Maíl Choluim (Modern Gaelic: Eagar mac Mhaoil Chaluim), nicknamed Probus, "the Valiant" (c. 1074 – 8 January 1107), was king of Alba from 1097 to 1107. He was the son of Malcolm III (Máel Coluim mac Donnchada) and Margaret of Wessex (later Saint Margaret). Edgar claimed the kingship in early 1095, following the murder of his half-brother Duncan II (Donnchad mac Maíl Coluim) in late 1094 by Máel Petair of Mearns, a supporter of Edgar's uncle Donald III (Domnall Bán mac Donnchada). His older brother Edmund sided with Donald, presumably in return for an appanage and acknowledgement as the heir of the ageing and son-less Donald.
Edgar received limited support from William II (William Rufus) as Duncan had before him; however, the English king was occupied with a revolt led by Robert de Mowbray, Earl of Northumbria, who appears to have had the support of Donald and Edmund. Rufus campaigned in northern England for much of 1095, and during this time Edgar gained control only of Lothian. A charter issued at Durham at this time names him "... son of Máel Coluim King of Scots ... possessing the whole land of Lothian and the kingship of the Scots by the gift of my lord William, king of the English, and by paternal heritage." Edgar's claims had the support of his brothers Alexander and David — Ethelred was Abbot of Dunkeld, and Edmund was divided from his siblings by his support of Donald — and his uncle Edgar Ætheling as these witnessed the charter at Durham.