The following index is based on William Petty's 1659 Civil Survey and Census as edited by Pender. It is based on the "Principal Irish Names". These where made up typically of the names of the old English, Hiberno-Norman's and Native Irish families. This Survey was carried out by Cromwell's Government, so most listed tended to be Royalist e.g. Cromwell's enemies. But it is a very useful bridge between names prior to the collapse of the regional Lords, be they Gaelige or Hiberno-Norman or the Old English and their more modern forms.

The following text is taken from the forward of "Irish Names and Surnames – Woulfe 1923 - Rev. Patrick Woulfe, Sloinnte Gaedheal is Gall: Irish names and surnames (1923) Ref. IE0014"

"It was only after the defeat of the Irish at Kinsale (1601) that what the Statute of Edward IV (1495) aimed at really began to be accomplished. Then set in the fashion of changing Irish into English surnames ; and it continued all through the 17th Century, until, after the fall of Limerick (1692), the Irish people were brought completely into subjection.
Thence forward an O' or Mac added to a man's name was no recommendation in the eyes of the powers that ruled the country. The people were taught or forced to believe that they must have an English surname, or at least an English version of their Irish surname. Hence the almost wholesale rejection of the O' and Mac during the long night of penal oppression through which Ireland passed into, the century of the penal laws (1710-1820). To reduce one's name as much as possible to the level of English pronunciation, to give it an English appearance, to modify it in some way and to some degree, was almost a condition of life. Fortunately, however, the original surname continued to live on, unaffected by any changes in the English form, wherever the Irish language continued to be spoken, and thus we are able to recover the Irish form of many surnames that otherwise would have long since disappeared for ever. In case we should think this to be a gross exaggeration, please read the following:
*The following appeared in the Cork Examiner of 2nd Feb., 1921 : " Miss Abina Corkery, MacCurtain St., Macroom, trading in the name of her deceased father, was obliged to remove from the facia board over the shop window the Gaelic characters 'Seamus O'Corcora'. She was informed by the authorities that failure to comply with the order within seven days would result in the burning down of the premises. The Irish inscription has been painted over."

About The Index Below

• Names grouped together on the same line are variants of that name.
• If there are a lot of variant names associated with a single surname and these move to a second row, the second row will have a blank space for the first name on the second row.
• Names with an Asterisk* where not in the original Census. The reason for entering these names with an asterisk is to preserve the historical integrity of the Index and at the same time provide a useful interactive index, connecting to existing DNA Surname projects.
• A coloured underlined name in the index, is a live link to an existing Surname DNA project or Clan website.
• If there are any errors or omissions please contact one of the administrators at the bottom of each webpage.
• For a definitive list of surnames always first refer to the comprehensive Irish Surname Index located on the FTDNA Irish heritage Public Webpage listed here: http://www.familytreedna.com/public/IrelandHeritage/

IMPORTANT: This list is not a complete list of surnames, a lot of Ulster names where omitted in the original census. If your name is not here contact one of the administrators and it will be added. This is not the definitive list of Irish names that IHDP is covering. There are 35,000+ Irish names and it is not practical to list them all.