Conn Ua Mellaig (died 1202) was the Bishop of Annaghdown. Ua Mellaig was a native of what is now County Galway, where his surname is now rendered Melia. He attended the coronation of Richard I of England on 17 September 1189. He died in office in 1202. Other bearers of the surname at Annaghdown included Bishop Tomas Ó Mellaig (c.1242-1247/50) and bishop-elect Tomás Ó Mellaig (fl. 1329).