Nave and chancel with transepts added later. W gable has blocked trabeate doorway with inclined jambs. Plain round-headed window in S wall of nave, splayed, with chamfered label.

Monastery founded in the 7thc by St Colman mac Duagh. The see is listed as a suffragen of Tuam on Cardinal Paparo’s list, and bishops of Kilmacduagh are recorded in the late 12th and 13thc.

The earliest part of the church is the W wall and doorway; the nave and chancel arch probably date from the later 12thc or c.1200. There is no Romanesque sculpture.

In the N transept is an engraved stone with a human face with large ears and pigtails, probably of later medieval date.