From LDS Ireland Research Guide:
In comparison to other countries, Ireland was slow in developing a newspaper industry. An occasional newspaper was printed in the mid-1600s. Ireland's major city and provincial newspapers began in the 1700s. Town newspapers began by the 1800s.
Pre-1750 newspapers included very little local news or other news of genealogical value. By 1750 newspapers included notices of marriages and deaths with increasing frequency. Still, few notices of births were published. Newspaper advertisements published such useful genealogical information as:
Changes in location or ownership of businesses.
Disputes over property ownership.
Notices of bankruptcies.
Notices of claims against estates.
By the 1800s, notices of births, marriages, and deaths became both more numerous and more detailed than in earlier newspapers. Advertisements, in contrast, generally became less genealogically useful as family businesses declined.
The following books contain chapters that more fully discuss newspapers as genealogical sources:
ffolliot, Rosemary. “Newspapers as a Genealogical Source.” In Irish Genealogy: A Record Finder, edited by Donal F. Begley (see the “For Further Reading” section).
Grenham, John. “Newspapers.” In Tracing Your Irish Ancestors: The Complete Guide (see the “For Further Reading”) section.
Copies of Irish newspapers are maintained by many repositories and libraries, including:
The British Newspaper Library. British Library, Catalogue of the Newspaper Library Colindale, 8 vols. (London: British Museum Publications, 1975; FHL book Q 942 A5cn; computer number 0182816) lists this library's newspaper holdings by town of publication. Volume two separately lists the library's Irish newspaper holdings.
The National Library of Ireland in Dublin. The National Library of Ireland, List of Newspapers on Microfilm (Typescript; FHL book Q 941.83/D1 A3n; film 990,403 item 7; computer number 0170368) provides a bibliography of the National Library's newspaper holdings.
Indexes of other Irish newspaper holdings include:
Crane, R. S., and F. B. Kaye. A Census of British Newspapers and Periodicals, 1620-1800. 2d ed. London: Holland Press, 1966. (FHL book 942 B3ce; computer number 0226560.) This book lists the Irish newspaper holdings of major U.S. libraries.
Newspapers in Microform: Foreign Countries. Washington, D.C.: Library of Congress, Catalog Publication Division, 1984. (FHL book 011.35 N479f 1983; computer number 0496878.) This source lists all reports from the foreign countries portion of Newspapers in Microfilm from 1948 to 1982, as well as reports received through 1983. This source is arranged by country and city and indexed by title.
North, John S. The Waterloo Directory of Irish Newspapers and Periodicals, 1800-1900. Waterloo, Ontario: North Waterloo Academic Press, 1986. (US/Canada Reference, FHL book Ref 941.5 B33n; computer number 0412814.) This book lists and describes Irish newspapers and periodicals from all fields and sometimes identifies their repositories.
The Family History Library has very few Irish newspapers. Those the library does have are listed in the Locality Search of the catalog under the following headings:
IRELAND - NEWSPAPERS
IRELAND, [COUNTY] - NEWSPAPERS
IRELAND, [COUNTY], [CITY] -