Glenahiry (Irish: Gleann na hUidhre[1]) is a barony in County Waterford, Ireland.

[4] The Nier joins the River Suir at Ballymakee.

[5] Glenahiry is located in northern County Waterford, east of the River Suir and west of the Comeragh Mountains.

The Nier Valley Woodlands are a Special Area of Conservation.

[6] Glenahiry was the ancient territory of the Mac Cairbre (Carbery).