St. Mary's Abbey is a medieval monastery and National Monument located in Duleek, Ireland.

[1] St. Mary's Abbey is located in the central part of Duleek called the Commons, between Main Street and Church Lane.

[2] In 1180 Hugh de Lacy, Lord of Meath granted Duleek (including St. Patrick's Church) to the Canons Regular.

The tower survives with four stories with quoins, battered walls, battlements, aumbry and stairs turret.

[5] The east window (bearing the arms of Sir John Bellew and Dame Ismay Nugent beneath it) is a 1587 post-Gothic replacement.