Legamaddy is a townland located in County Down, Northern Ireland, within the civil parish of Bright and the barony of Lecale Upper. The Irish name for Legamaddy is "Lag an Mhadaidh," which translates to "Hollow of the Dog."

Legamaddy is situated near Downpatrick, a town known for its historical significance, including connections to St. Patrick. The townland covers an area of approximately 85.63 hectares (211.59 acres) and is bordered by several other townlands, including Ballydargan, Ballynoe, and Coniamstown.

There is a small lake at the south-west corner of the townland, which may be the ‘hollow’ referred to in the place-name. Legamaddy was originally called Carrowmalt. It has also been recorded in deeds of 1729 and 1760 as Catrowmaltagh, to be otherwise Legamuddy, Liag-na-mnda, “the dog’s stone.”

It was owned by Thomas Cromwell, 3rd Earl of Ardglass, in 1669 and leased to Patrick Shane from 1637 to 1669, who then sublet it to William Hamilton Esq. The name of this townland seems to have no recorded mention before 1710 when it had a slightly different spelling (Leggamaddy). In 1755 it was named Liggmaddy and in 1868 it was known as Liggamaddy.

The population of Legamaddy in 1841 was 57.

St. Patrick's Legamaddy, erected in 1865 by Fr. Richard Killen, Parish Priest, celebrated its 150th anniversary in 2015. This church was built to replace the former church at Coniamstown, which dated back to before 1745. The original Catholic chapel in Coniamstown was erected around 1745 and re-roofed and slated in 1796. By 1836, this chapel, described as having no seats but accommodating 400 people. It was replaced by the new church in Legamaddy townland with the foundation stone laid on August 27, 1862.

Following the Great Famine, the Catholic Church in Ireland, along with the diocese of Down and Connor, began revitalizing efforts to support and organize their congregation enabled by the Emancipation Act of 1829. Archbishop Paul Cullen of Armagh led these initiatives. The Great Famine had been a devastating blow, but with over a decade having passed, there was now momentum to establish new catholic churches as well as new primary and secondary schools. So it was in these times that Saint Patrick's Church was designed in the early Gothic style by architect Mr. John O'Neill from Belfast. In addition to working on Legamaddy Church, where he was responsible for designing and preparing drawings and documentation for tendering, he was also actively involved in designing and preparing tender documents for the Church of St. Mary, Star of the Sea, in Whitehouse, Newtownabbey. A notice to builders regarding this project was published in the Belfast Morning News on Saturday, November 29, 1862.

The church's architectural elements include a long nave, square ended chancel, a clearly expressed sacristy, porches (on the north, south and western sides of the church). The church also tower features a large, square, and squat tower with corner buttresses and a recessed pointed arch doorway. However, the tower remains incomplete due to insufficient foundations, which were unable to support the originally planned eighty-foot tower with an embattled parapet.