Diarmait mac Máel na mBó

Diarmait mac Máel na mBó (died 7 February 1072) was King of Leinster and, with opposition, High King of Ireland. In 1042 he made himself king of Leinster and installed his son Murchad as king of Dublin. Allied with the king of Ulaid, he pressed the kingdoms of Mide and Brega.

After 1066 he sheltered the sons of King Harold Godwinson and lent them the Dublin fleet for invasions of England in 1068 and 1069. He was killed fighting Conchobar Ua Máel Sechlainn of Mide at the battle of Odhbha on 7 February 1072.