In 1868, the parish of Castlemore contained the following places:
"CASTLEMORE, a parish partly in the barony of Costello, in the county of Mayo, and partly in the barony of Frenchpark, in the county of Roscommon, province of Connaught, Ireland, 1 mile to the W. of Ballaghaderreen. The soil is poor, and there is much bog. The living is a vicarage in the diocese of Tuam, Killala, and Achonry, value with two other benefices, £248, in the patronage of the bishop. The principal residences are Castlemore House and Brooklawn, the latter being that of the Roman Catholic bishop of Achonry."