National Archives of Ireland: The National Archives of Ireland was once the Public Record Office of Ireland. You can access some information on doing your family history research.
Public Record Office of Northern Ireland: PRONI is a must visit website for all those researching their Northern Irish ancestors. They have a wonderful free digital collection.
National Library of Ireland: The NLI has a section on family history and they house a large Irish newspaper collection. You can access the Sources database from this website.
Linen Hall Library Northern Ireland: The Linen Hall Library in Belfast was founded in 1788 and is the oldest library in Belfast. It has a large Irish and Local Studies Collection.
Irish Genealogy: The official government website where you can access some church records as well as census, Tithe Applotments, Soldier’s Wills, Griffith’s Valuation, Ireland – Australia Transportation Database and other databases.
Irish Genealogy Toolkit: A great resource for anyone doing Irish research. The information on this website is free.
Findmypast Ireland ($$): A subscription database dedicated to Irish records.
General Register Office Ireland: The place to order your Irish birth, marriage and death records. After 1922 only records for the Republic can be accessed here.
General Register Office Northern Ireland: The place to order your birth, marriage and death records for Northern Ireland.
Church of Ireland: The Church of Ireland website where you can find out about the church in Ireland and access their digital archive. The digital archive is small but growing.
Presbyterian Historical Society of Ireland: The place to search for your Presbyterian ancestors in Ireland.
Quaker Historical Archive and Library Ireland: They hold records relating to Quakers in Ireland.
Genealogical Society of Ireland: Formerly the Dún Laoghaire Family History Society, the Genealogical Society of Ireland promotes genealogy in Ireland.
Irish Family History Society: Formed in 1984 to help the Irish Diaspora with their family history research.
North of Ireland Family History Society: They encourage the interest in family history in the six counties of Northern Ireland.
Ireland Genealogy Projects Archives: A site created by volunteers uploading genealogical records. It is listed by County.