Flaithnia mac Flainn (died 755) was a king of the Uí Failge, a Laigin people of County Offaly.
He was one of the many sons of Fland Dá Chongal, a previous king.
[2] His predecessor and half-brother Ailill Corrach mac Flainn was killed in 741 but the circumstances are not given.
[4] His son Domnall mac Flaíthnia (died 783) was a king of the Uí Failge.
[citation needed] This biography of a member of an Irish royal house is a stub.