It was thought to be the principal church in a group which included Kilmegan and Kilcoo despite the fact that Kilkeel was very sparsely populated in the Middle Ages.

The last burials at the cemetery were victims of a collision between two steamers, the Retriever and the SS Connemara, in Carlingford Lough.

The earliest recorded dates are a kerbstone inscribed 1772, and a second story arch window in Newry St inscribed 1790, while the map alongside from 1777 shows that Kilkeel's current layout of 5 main streets was already established.

[5] There are fish-processing factories around the port, pleasure angling off the piers and lobster farming along the coastline.

As of 2014, its Kilkeel facility, which manufactures aircraft seats for a worldwide customer base, employed over 800 people.

Prince Harry, Duke of Sussex, grandson of the late Queen Elizabeth II and son of King Charles III of the United Kingdom was granted the title Baron Kilkeel along with that of Duke of Sussex and Earl of Dumbarton.

On census day 2011, 27 March 2011, there were 6,541 people living in Kilkeel (2,557 households), accounting for 0.36% of the Northern Ireland total.

Kilkeel Elks Basketball Club was based at An Ríocht Hall, it is now defunct.

It was created on 19 May 2018 by Queen Elizabeth II as a substantive title for her grandson Prince Harry on the occasion of his marriage to Meghan Markle.