The structure dates back to the 12th or 13th century, though the site itself may have earlier religious significance. What remains today are the weathered stone walls of the nave and chancel, with the characteristic pointed arch windows typical of medieval Irish church architecture. The building would have served the local community for centuries before falling into disuse, likely during the Reformation period when many such churches were abandoned.

The church’s most striking feature is its east window, a triple lancet design that would have flooded the altar area with morning light. The doorway on the south wall shows signs of later modifications, suggesting the building evolved over its active lifetime to meet changing needs. Stone corbels jutting from the walls once supported a wooden roof that has long since vanished, leaving the structure open to the Clare skies. The surrounding graveyard contains headstones dating from the 18th century onwards, though earlier burials almost certainly lie unmarked beneath the grass.

Local tradition holds that the church was dedicated to Saint Inan, who founded several religious sites across Clare in the early medieval period. The name Killinaboy itself derives from the Irish ‘Cill Iníne Baoith’, meaning ‘church of Inan the foolish’; a peculiar epithet that may reference the saint’s reputation for unconventional wisdom. Today, the ruin stands as a peaceful reminder of the area’s long Christian heritage, with wild grasses and ivy slowly reclaiming the ancient stones whilst cattle graze in the adjoining fields.