Uí Fiachrach Finn was a territory located in Máenmaige in what is now central County Galway.
It was home to the families of Ó Maolalaidh and Ó Neachtain. By the 15th century the Ó Maolalaidh's had been expelled and settled north of Tuam, while the Ó Neachtain's had been forced to relocate in the Fews of Athlone.
References
Ui Fiachrach Finn Wikipedia(Text) CC BY-SA