Built with rounded corners, the structure measures 13.3 metres east to west and 10.2 metres north to south. Though its imposing walls remain largely intact, the castle has suffered significant losses over the centuries; a local farmer reportedly stripped away most of the dressed stone details, including the window surrounds and door frames, leaving the tower somewhat bare of its original architectural flourishes.

The castle’s internal layout reveals the sophisticated defensive planning typical of 15th-century Irish tower houses. Entry through the eastern ground-floor door leads into a lobby covered by a murder hole, beyond which lies the main chamber. A square guard chamber branches off to the north, whilst spiral stairs to the south wind their way up through all five floors, providing access to both the main chambers and several mural rooms built into the thick walls. Each floor served different purposes: the second floor housed the main living quarters, complete with a fireplace in the north wall and a garderobe, whilst defensive features include gun loops and bartizans; angular projections supported by corbels that once defended the corners, though only the northeastern example survives intact.

The castle’s history remains somewhat disputed amongst historians. Writing in 1750, Smith attributed the castle to the O’Donoghues, but local tradition recorded by Lee in 1914 suggests it was erected by Dermot MacCarthy in 1436, whilst Lewis, writing in 1837, dated the construction to 1445 and credited it to the McCarthy family. What seems certain is that by the 17th century, a branch of the O’Mahony clan had taken possession of the tower. Today, despite its weathered state and missing architectural details, Kilmeedy Castle stands as a remarkable example of late medieval Irish fortification, its vaulted ceilings and complex internal arrangement testament to the engineering skills of its builders.