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The purpose of this project is to learn more about the origins and distribution of the Coursey/DeCoursey surnames, as well as act as an aid to traditional genealogical research. This Y-DNA project is open to all males with any variation of the Coursey or DeCoursey surnames, as well as males who believe they are a direct male descendant of a Coursey or DeCoursey. Participants from all testing companies are welcome, although we recommend using FTDNA. Participants are sought from all over the world, all origins and ethnicities are welcome.

Examples of surname variations:
Coursey, Courcy, Courcey, Corsey, Course, Corse, Courson
de Courcy, de Courcey, DeCourcy, DeCourcey, DeCoursey, DeCorsey, DeCourse

This project currently has 28 members, most with either Irish or early southern US origins. So far we have identified 6 distinct genetic lineages. Six project members have not yet found matches. (See the Y-Results page for more information.) We are actively seeking more participants of any origin. The project is especially interested in obtaining participants from (de) Courcy lines of French or French Canadian origin. Free tests are available for certain lineages, see link below. Contact the project administrator for more info.

For information on how to join go to the "Join Project" page.
There is a collection of links to more information on DNA testing on the "Help" page.

Free and rebated tests are available for participants from certain lineages and places of origin, see the "WANTED!" page for more info.

Project News (Sep 2011):

  • The results from participant C-20's 67-marker upgrade are in! Like participant C-3, he is descended from the Courseys of Logan County, KY. His results show that there is a pattern that distinguishes the Logan County, KY and Edgefield County, SC Coursey lines from the others in Group 1, so it has now been subdivided into two sections - one containing lines of known Irish origin, and the other with the early southern US lines.
  • A Wanted! page has been added. It lists lines and places of origin that are of special interest to the project, descendants of these are eligible for free or rebated tests.


The main objectives of this project are to:

Find participants from as many different Coursey/DeCoursey lines as possible and divide them into distinct genetic lineages.

Try to determine if it is possible to distinguish between lines which originate from different counties in Ireland.

Sort out the relationship (or lack thereof) between the Coursey lines who emigrated to the United States pre-1750.

Study the origins and history of the surnames and genetic lineages.

Aid genealogical research by validating existing research and making new connections to other families.

Bring down a few genealogical "brick walls".

Some of the questions this project hopes to answer:

  • Which of the Coursey lines who were in North America before 1800 are related to Col. Henry Coursey who emigrated from Dublin, Ireland to Virginia and then Maryland around 1650?
  • What is the genetic signature of the de Courcy Barony of Kinsale, County Cork, Ireland?

Surname Meanings and Origins
Coursey: Irish (of Norman origin): habitational name from any of various places in northern France called Courcy, from the Romano-Gallic personal name Curtius (a derivative of curtus ‘short’) + the locative suffix -acum. Compare Decoursey. (Dictionary of American Family Names, Oxford University Press, ISBN 0-19-508137-4)

DeCoursey: English and Irish (of Norman origin; also written De Coursey): habitational name for someone from any of various places in northern France called Courcy, from the Romano-Gallic personal name Curtius (a derivative of Latin curtus ‘short’; compare Court 2) + the locative suffix -acum. (Dictionary of American Family Names, Oxford University Press, ISBN 0-19-508137-4)

Courcy: French: habitational name from any of the places in Calvados, Loiret, Manche, and Marne called Courcy. (Dictionary of American Family Names, Oxford University Press, ISBN 0-19-508137-4)

De Courcy: Quite numerous: scattered. Ir. de Cúrsa. Norman Sir John De Courcy came to Ireland in 1177. They have been mainly associated with Cork. SGG. (Sloinnte na hÉireann-Irish Surnames Le/By Seán de Bhulbh, Comharchumann Íde Naofa, 1997, ISBN 0-9530560-1-5)


Links to info on Coursey and DeCoursey surnames and variations:


Historical Genealogies and Information:

  • The Coursey Surname and the Town of Courcy - History of the surname, pictures


    Project Member Websites:


    Useful Links

    World Families Network Forums

    Coursey/DeCoursey Family Forum

    Click here to order a DNA test now

    For basic information, visit World Families Network and check out the "Getting Started" block


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    Project Administrators