Recorded in an amazing number of spellings including MacIlroy, MacElroy, McIlroy, McElroy, McLeroy, McGilroy, McAlroy, McAlvey, MacElvey, McKelvie, McKelvy, McLevie, McLevy, and probably others, this is both a Scottish and Irish surname. It is a developed form of the Gaelic "Mac giolla Ruaidh", composed of the elements "Mac", meaning son of, "giolla", the youth, and "ruaidh", red haired; hence, "The son of the red haired youth". In Scotland the clan originated from Ballantrae in Aryrshire as shown below, whilst in Ireland it is first recorded in County Fermanagh, where the place Ballymackilroy is to be found, although there are two other places so named in County Tyrone and County Antrim. Traditionally Gaelic family names are taken from the heads of tribes, or from some illustrious warrior. Presumably the first of this clan had very prominent appearance, in addition to his youthfulness. Michael Mak Gilroy also recorded as Michael M'Ylroye, was the baillie of Ayr in 1488, whilst in Ireland the clan were frequently mentioned in the famous historical book known as the Annals of the Four Masters. The Rev. John McElroy, (1782 - 1877), was associated with the illfated uprising of the United Irishmen in 1798, and later became famous in America as a church builder. Mary McElree was recorded in Maghera, County Derry, on June 5th 1845, and James McLevie at Banbridge, County Down, on February 20th 1865. The first recorded spelling of the family name is shown to be that of Michael M'Gilrey. This was dated 1376, in the Ancient Charters of the earldom of Morton, during the reign of King Robert 11nd of Scotland, 1371 - 1390. Throughout the centuries surnames in every country have continued to "develop", often leading to astonishing variants of the original spelling.