Uí Fhiachrach Aidhne (also known as Hy Fiachrach) was a kingdom located in what is now the south of County Galway.
On the north-east Aidhne is bounded by the plains of Uí Mhaine and on the north by Maigh Mucruimhe (the area around Athenry).
The diocese of Kilmacduagh contains the present Catholic parishes of Kinvara, Ballinderreen, Gort, Ardrahan, Craughwell, Beagh, Kilbeacanty, Kilthomas (Peterswell), Clarinbridge, Kilchreest.
In the early historical era, the Aidhne branch of the Ui Fiachrach dynasty emerged as the ruling tuath in this part of Connacht.
Up until the late 17th century the O Shaughnessys held the sub district of Uí Fhiachrach Aidhne known as Cenél Áeda na hEchtge, which was also their clan name.
The Irish annals contain some references to the family: Noted bearers of the name include: Kilkellys held the sub-district of Aidhne known as Cinéal nGuaire, which is the area covered by the modern Catholic parish of Ballinderreen.