It is widely regarded as having been founded in 1451,[3] with most local historians taking this date from an 1890 translation of the Latin text, Muniments of the Royal Burgh of Irvine.

[1] At or soon after its foundation, the revenues of Loudoun Kirk, were allocated to support the monks of the newly founded Kilwinning Abbey, however they were obliged to provide a priest (curate) to attend to the spiritual needs of the parishioners.

John Nevoy of Loudoun Kirk was the chaplain to the Covenanter army led by General Leslie who were fighting the Irish MacDonnels who had invaded the west of Scotland.

[1] Francis Rawdon-Hastings, 2nd Earl of Moira and Marquess of Hastings, died on 28 November 1826 aboard HMS Revenge (1805) off Naples and following his directions his right hand was cut off and buried with his wife, Flora Mure-Campbell, Marchioness of Hastings and 6th Countess of Loudoun (1780 – 8 January 1840) who was the second daughter of James Mure-Campbell, 5th Earl of Loudoun and Lady Flora Macleod.

[6] Recently, Friends of Loudoun Kirk completed a survey of the headstones and plaques found within the graveyard, with the findings being made available to the public via digital media.

[8] In February 1944, the 5th SAS, under Lieutenant-Colonel Eddy Blondeel (then Captain), was stationed at Loudoun Castle to train for the D-Day Landings of the same year.