Irish clans are officially recognized groups of people who either share a surname or are descended from people who bore the surname. Since 1989, the government of the Republic of Ireland has recognized a charity called "Clans of Ireland" as the official registrar of these groups. Based at Athenry in County Galway, it is similar to a genealogical society with an additional social dimension. To date, more than 230 clans have registered. For a complete listing, visit the charity's website at http://www.theclansofireland.org/ .

There are several requirements for recognition as an official Irish clan:

• The surname must have a documented history in Ireland prior to the Irish Potato Famine.
• Membership must be open to any bearer of the surname (or descendant thereof) regardless of race, religion, or gender.
• Membership must include at least six adult bearers of the surname.

Note that each clan may be divided into septs to reflect the religious, geographic, historic, and cultural diversity within the surname group.