The current church was constructed where a 17th century parish church once stood, surrounded by its original graveyard that still serves the community today. Archaeological records from 1996 note that the earliest documented gravestone dates to around 1620, though its exact location within the graveyard has proven elusive to modern researchers.

The graveyard holds particular historical interest for its early memorials, including what local tourist information identifies as one of the oldest marked graves; that of Henry Wray, who died in August 1652. Despite its documented importance, this memorial has similarly evaded recent attempts at location. What can be found are two notable graveslabs positioned roughly twelve metres south of the church. One features a substantial armorial plaque, though time has worn away its inscription beyond legibility. Its companion slab nearby displays characteristics suggesting it too may date from the 17th century.

These weathered stones represent tangible links to Letterkenny’s early Protestant community, established during a turbulent period of Irish history. While the precise identities of those commemorated may be lost, the survival of these monuments, compiled and documented by archaeologist Caimin O’Brien in July 2010, offers valuable insight into the town’s colonial past and the establishment of its religious institutions during the plantation era.