The parish of Peterswell is situated in south County Galway , 3 miles east of the town of Gort. It borders the Ardrahan parish in the north and stretches across the Slieve Aughty Mountains to the county Clare border, a distance of almost 10 miles. On the western side it adjoins the parishes of Kilbeacanty and Gort with Ardrahan, Kilchreest and Derrybrien to the east. It has an area of 11,700 acres. The parish includes part of 2 baronies, Loughrea and Kiltartan and 41 town lands, 24 and 17 in each barony respectively. The official name of the parish is Kilthomas.