At 6°03′46″W, it is the easternmost of the Republic of Ireland's National Monuments.

[3] The church was built in the 12th century and was dedicated to Mary, mother of Jesus.

Thady Byrne of Ballygannon, a senior member of the O'Byrne family, was buried at Kilcoole Church in 1707.

The nave has a square baptismal font, a cross slab and a small round-headed window in the south wall.

[5] The west part of the church was added later as a two-storey living quarters.