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.[1] He ruled from 741 to 755.[2]
His predecessor and half-brother Ailill Corrach mac Flainn was killed in 741 but the circumstances are not given.[3] Nothing is recorded of Flaithnia in the annals other than his death obit.[4]
His son Domnall mac Flaíthnia (died 783) was a king of the Uí Failge.