| 14276 | Alexandra College | | 1866-1966 | Centenary Booklet, 1866-1966. | |
| 19161 | Armagh Robinson Library | Volume 1960-1969 | 1830-1966 | Unindexed and miscellaneous volume, mainly containin... | Dean Rennison Papers |
| 23890 | Brother Allen Archive | Box 184 | 1966 | Letter to Mrs Florence Monteith Lynch implicating Br... | Brother Allen Archival Collection |
| 16782 | Cashel, Ferns and Ossory Diocesan Archive (CoI) | | 1946-1966 | Minutes of Meetings and Accounts of Friends of Cashe... | Bolton Library Archive |
| 15028 | Catholic Girl Guides of Ireland | | 1966-1970 | Catholic Girl Guides of Ireland, Log-Book:September ... | |
| 15099 | Catholic Girl Guides of Ireland | | 1940-1966 | House Committee Cash Book, Catholic Girl Guides of t... | |
| 6104 | Clare County Archives | | 1966 | Council Attendance Register, 27 June 1966 - 1 Septem... | Clare County Council |
| 6105 | Clare County Archives | | 1966 | Council Attendance Register, 27 June 1966 - 1 Septem... | Clare County Council |
| 6158 | Clare County Archives | | 1965-1966 | Record of Voting of County Councillors, 1965 - 1966... | Clare County Council |
| 14378 | Clare County Archives | | c.1920-1966 | Bluett Photograph Collection:257 photographs of the ... | Clare County Library Photographic Archive |
| 13263 | Cork City and County Archives | | 1898-1966 | Malicious Injury Claims, 1920, 1921 (police reports)... | Cork County Council Minutes 1898-1966 |
| 13795 | Cork Public Museum | AQNOL1996:133 | 1965-1966 | Letters to Nora Wallace from 'Cathal', 19 Ju... | Nora Wallace Collection |
| 20758 | Cork Public Museum | AQNOL1996:143 | 1966 | Letter to Nora Wallace from Ina Connolly, 24 June 19... | Nora Wallace Collection |
| 22949 | Down and Connor Diocesan Archive (RC) | A-T | 1966-1969
1914 | O. Information relating to the Orphan Society, inclu... | |
| 19885 | Erasmus Smith Schools Archives | | 1945-1966 | Board and Committee Agenda Book and Rough Agenda Boo... | Erasmus Smith Archives |
| 1417 | Fingal County Archive | DCC/L/47 - DCC/L/50 | 1926-1966 | DCC/L/47 March 1955 - November 1959 Rathdown Board o... | Dublin County Council |
| 1451 | Fingal County Archive | | 1908-1966 | 93/CP/1 II. Material relating to the financial deali... | Dublin County Council |
| 20013 | Fingal County Archive | 97/LA/1/25-97/LA/1/26 | 1966-1977
1904-1909 | Agenda and Order Book:97/LA/1/25 November 1966 - Sep... | Records of Balbriggan Town Commissioners |
| 23188 | Grand Lodge of Freemasons of Ireland | | 1942-1966 | Head Girls' Book, 1942-1966 | Masonic Female Orphan School |
| 23189 | Grand Lodge of Freemasons of Ireland | | 1966-1972 | Headmistress' Report Book, 1966-1972 | Masonic Female Orphan School |
| 5558 | Irish Federation of University Teachers | | 1965
1966 | Administrative Records. Minute Books: Council, 1965-... | |
| 207 | Irish Film Archive | Turkana | 1966 | 'Turkana': Production Company: Radharc A R... | |
| 377 | Irish Film Archive | To See Old Shannon's Face | 1966 | 'To See old Shannon's Face Again': Film... | |
| 390 | Irish Film Archive | Ireland: the news confere | 1966 | 'Ireland: the news conference country': Pro... | |
| 24531 | Irish National Teachers' Organisation | | 1868-1903
1904-1966 | Union Journals: Irish Teachers Journal, 1868-1903 Ir... | |
| 24563 | Irish Nurses and Midwives Organisation | | 1966-1972 | Storage box 2 containing 4 large envelopes, Executiv... | Irish Nurses' Organisation |
| 20849 | Kildare Local Studies, Genealogy and Archives Department | | 1960-1966 | County Home, Athy:Telephone Call (Personal) Account ... | Kildare Board of Health Records |
| 1791 | King's Hospital School | 5/ | 1966 | 15 Mercers's school. Memorandums regarding merge... | Mercer's School |
| 21071 | King's Hospital School | 145-160 | 1959-1966 | 157A Wages Book, 1959 - 1966. | King's Hospital Records |
| 21166 | King's Hospital School | 232-236A | 1915-1966 | 236 Birth Certificate, Record Book, 1915 - 1966. | King's Hospital Records |
| 21167 | King's Hospital School | 232-236A | 1917-1966 | 236A Examination Marks Book, 1917 - 1966. | King's Hospital Records |
| 5605 | Laois Local Studies | | 1900-1966 | Minute Books, 1930-1939, 6 volumes. Receipt Book, 1... | Maryborough District Lunatic Asylum |
| 14494 | Mayo Local History Department | | 1948-1966 | Register of Insurances, 1948-1966 | Mayo County Council |
| 14495 | Mayo Local History Department | | 1962-1966
1908 | Register of Licences granted under the Pharmacy and ... | Mayo County Council |
| 739 | National Archives of Ireland | BG/79/FN1 | 1966-1970 | Porter's Books: October 1966 - January 1970 | South Dublin Poor Law Union and Rural District Council |
| 4722 | National Archives of Ireland | | 1952-1966 | National School Registers: Roll No. 17144 County Lon... | Department of Education |
| 4938 | National Archives of Ireland | C&A4664/53/Volume2 | 1964-1966 | C&A Departmental Council, question of recruitment to... | Department of Transport, Energy and Communications |
| 4940 | National Archives of Ireland | E4/7/49 | 1966-1968 | File on EEC pay discrimination between males and fem... | Department of Transport, Energy and Communications |
| 4944 | National Archives of Ireland | 1088/839, 1088/839/1, 108 | 1966-1972, 1968 | File on the Sliabhbawn Co-operative Handcraft Market... | Irish Agricultural Organisation Society |
| 11301 | National Archives of Ireland | 397/17 | 1939-1966 | Consular Section Files: Hospitals New Book: London E... | Department of Foreign Affairs |
| 14025 | National Archives of Ireland | Accession no. 1138 | 1863-1966 | National School Records for North King Street, Dubli... | |
| 11988 | National Archives of Ireland | GIS/1/312 | 1965-1966 | Speeches by Donogh O'Malley as Minister for Health, ... | Government Information Service |
| 12066 | National Archives of Ireland | 98/5/3/I-XI | 1929-1966 | General Correspondence 98/5/3/I 1929-1932 Correspon... | Irish Girl Guides |
| 11187 | National Gallery of Ireland Library | AB125 | 1944-1966 | Material relating to G B Shaw, includes: Postcard fr... | |
| 2735 | National Library of Ireland | Ms20835 | 1966-1969 | Correspondence of John Whyte with Eileen C Penney, H... | Adoption Society (Ireland) Papers |
| 9229 | National Library of Ireland | Ms15469 | 1911
1966 | Photocopy of notes by James Cryan, 1966, on Miss Agn... | |
| 10816 | National Library of Ireland | Ms18816 | 1914-1966 | Drafts of articles and notes by Mrs Czira (pseudonym... | Mrs Sydney Czira Papers |
| 10817 | National Library of Ireland | Ms18817 | c1927-1966 | Drafts of articles, scripts of broadcasts and notes ... | Mrs Sydney Czira Papers |
| 10823 | National Library of Ireland | Ms18824 | c1916-1966 | A collection of songs and poems, includes, among oth... | Mrs Sydney Czira Papers |
| 10826 | National Library of Ireland | Ms18827 | c1923-1966 | Miscellaneous items relating to Mrs Czira, includin... | Mrs Sydney Czira Papers |
| 10965 | National Library of Ireland | Ms22588 | 1958-1966 | Miscellaneous correspondence which includes 2 letter... | W.G. Fallon Papers |
| 85 | National Maternity Hospital | H/11 | 1954-1966 | House Committee, Agenda Book, October 1954-July 1966... | |
| 466 | National Maternity Hospital | E/13/5 | 1960-1966 | Executive Committee Agenda Book, November 1960-May 1... | |
| 5402 | Newtown School, Waterford | A1/6 | 1956-1966 | Entry Policy, 1956-1966: Newtown School, Waterford | |
| 5507 | Newtown School, Waterford | | 1956-1966 | Entry Policy, 1956-1966: Newtown School, Waterford | |
| 18874 | Offaly Archives | OCL ETC35 | 1947-1966 | 1 Artisans Dwellings General Rental -
ETC35/7: 31... | Records of Edenderry Town Commission |
| 18916 | Offaly Archives | OCL OFCC10/9 | 1966 | 1966 Commemorations Committee | Records of Offaly County Council |
| 21375 | Our Lady's Hospital, Ennis | | 1942-1966 | Managers' Orders Books:September 1942-July 1948S... | |
| 6726 | Public Record Office of Northern Ireland | D/2054 | 1936-1966 | 27 volumes of annual reports and accounts of the Cha... | |
| 7201 | Public Record Office of Northern Ireland | D/3079 | 1966-1970 | Papers of the National Democratic Party, including m... | |
| 7259 | Public Record Office of Northern Ireland | D/3435 | 1883-1966. | c.1000 admission slips for internments in Friar'... | |
| 6572 | Public Record Office of Northern Ireland | D/1633 | 1899-1966 | Diaries of Lilian, Lady Spender (née Dean), w... | Spender Papers |
| 6610 | Public Record Office of Northern Ireland | D/1732 | c1960-1966 | D/1732/4/1-4 Volumes of duplicated minutes of Belf... | |
| 6732 | Public Record Office of Northern Ireland | D/2072 | 1934-1966 | Minute book of the Belfast Midnight Mission for unma... | |
| 6758 | Public Record Office of Northern Ireland | D/2133 | c.1790-c.1966 | c.350 documents relating to the Rowan family, County... | |
| 6799 | Public Record Office of Northern Ireland | D/2305 | 1957-1966 | Minute Book of the Belfast and District Branch of Na... | National Union of Journalist Papers |
| 6848 | Public Record Office of Northern Ireland | D/3485 | 1966-1991 | Records of the Northern Ireland Citizen's Advice Bur... | |
| 7020 | Public Record Office of Northern Ireland | D/2548 | 1757-1966 | The Gardner papers comprise of c.1,000 documents, 17... | Gardner Papers |
| 7054 | Public Record Office of Northern Ireland | D/2656 | 1895-1966 | c.120 documents comprising of the records of David A... | |
| 7173 | Public Record Office of Northern Ireland | D/3010 | 1830-1966 | c.150 documents relating to the Orr/Newton family, 1... | |
| 7374 | Public Record Office of Northern Ireland | D/3846 | c1906-1966 | 13 volumes and c500 documents relating to Doctor Ne... | Robb Papers |
| 7431 | Public Record Office of Northern Ireland | D/4025/4 | 1966
1968-1969. | Correspondence about Sir Patrick Arthur Macrory'... | |
| 7483 | Public Record Office of Northern Ireland | D/4151 | c.1620-1966 | The Kenmare papers comprise of c.400 volumes and c.3... | Kenmare Papers |
| 7657 | Public Record Office of Northern Ireland | LA/12 | 1922-1966 | Local Authority records are closed for 30 years from... | Ballymena Urban District Council and Borough Council Records |
| 8272 | Public Record Office of Northern Ireland | T/2259/1 | c.1966 | Family tree of the Reids, Kells, County Antrim, c.18... | |
| 8287 | Public Record Office of Northern Ireland | T/2305/ | 1786-1966 | This collection of 39 documents includes: T/2305/9 C... | |
| 8290 | Public Record Office of Northern Ireland | T/2315/ | 1924-1966 | T/2315/1 A pedigree of the Faussett family, Willsbor... | |
| 8299 | Public Record Office of Northern Ireland | T/2348 | 1329-1900
1966 | Typescript notes on the history of the Moneypenny fa... | |
| 8302 | Public Record Office of Northern Ireland | T/2356/1-2 | 1685-1966 | 2 pedigrees of the Breakey families in Drumskelt and... | |
| 8308 | Public Record Office of Northern Ireland | T/2369/2 | 1752-1966 | Genealogical notes on the family of Armstrong, Culmo... | |
| 8341 | Public Record Office of Northern Ireland | T/2468/1-8 | 1966-c.1968 | Typescript and manuscript genealogical material on t... | |
| 8378 | Public Record Office of Northern Ireland | T/2565/1A-2B | 1600-1966
1720-1943 | Family pedigrees and stat negative files of the Kyle... | |
| 8463 | Public Record Office of Northern Ireland | T/2750/1 | 1834-1966 | Copy of the session minute book of the 3rd Cookstown... | |
| 8473 | Public Record Office of Northern Ireland | T/277/4/2 | c.1966 | Typescript account of the murder of Betsy Gray in 17... | |
| 8741 | Public Record Office of Northern Ireland | TP/1 | 1966 | Audio tape-recording of Lady Stronge's speech delive... | |
| 863 | Religious Society of Friends in Ireland Historical Library | Mss Box 3-3a | 1966
1971 | Mss Box 3 Miscellaneous relating to Lydia Jane Fish... | Handlists: Mss Boxes, Pamphlets Boxes, etc. |
| 1279 | Religious Society of Friends in Ireland Historical Library | MMII/J1-22 | 1720-1966 | Accounts: MMII/J1 Poor Accounts, 1720-1748. 'A Coll... | Dublin Monthly Meeting |
| 2160 | Representative Church Body Library | Ms264 | 1924-1966 | Minutes of Bethany Home, Dublin, founded to care for... | Bethany Home |
| 22085 | Representative Church Body Library | B5 | 1895-1900
1901-1907
1966 | St Fin Barre's Parish, Register of Parishioners:... | St Fin Barre's Cathedral Cork Archive |
| 23725 | Representative Church Body Library | | 1723-1966 | St Patrick's Parish: Combined Register, 1723-1773, 1... | Waterford Cathedral |
| 23736 | Representative Church Body Library | MS607/ | 1954-1966 | Financial Records: 10/ Infirmary Account Books: 1: 1... | Records of the Mageough Home, Dublin |
| 23737 | Representative Church Body Library | MS607/ | 1957-1963
1964-1966 | Financial Records: 11/ Cash and Credit Analysis Book... | Records of the Mageough Home, Dublin |
| 23740 | Representative Church Body Library | MS607/ | 1963-1966 | Financial Records: 14: Chemists' Supplies Account Bo... | Records of the Mageough Home, Dublin |
| 2380 | Royal Irish Academy | Ms12/O/24 | 1900-1966 | Correspondence from Celtic and other scholars, 1900-... | Eleanor Knott |
| 22480 | Royal Victoria Hospital, Belfast | | 1961-1966 | 1 volume of Ophthalmic/Benn Hospital Minutes:1961-19... | |
| 24646 | RTÉ Archive (Television) | | 1966 | 10 November 1966, News Mrs Maureen Lynch on being wi... | Television Programme Archive |
| 24647 | RTÉ Archive (Television) | | 1966 | 25 December 1966 'Bells and Blue Berets', UN soldier... | Television Programme Archive |
| 22724 | South Eastern Education and Library Board Local History Collection | | 1966-c.2000 | Antrim County Council Minutes: 1966- (boxed) | Local Studies Collection |
| 22022 | St Brigid's Hospital, Ballinasloe | | 1966-1967 | Ballinasloe District Lunatic Asylum, Mental Treatmen... | Ballinasloe District Lunatic Asylum |
| 22023 | St Brigid's Hospital, Ballinasloe | | 1963-1966
1967-1968 | Expenses Book, [Castlerea Mental Hospital?]:1963-196... | Ballinasloe District Lunatic Asylum |
| 12111 | St Louis' Heritage Centre | MCG12/GB30-MCG13/GB30 | 1940
1966 | Photographs relating to Mother Columbanus Greene, Mo... | |
| 10404 | Trinity College Dublin, Manuscripts and Archives Department | TCDMs10068 | 1938-1966 | Correspondence of Ina Boyle, concerning genealogical... | Ina Boyle Papers |
| 11908 | Trinity College Dublin, Manuscripts and Archives Department | TCDMs10381/81-182 | 1921-1966 | Letters to Thomas Mac Greevy, 1921-1966, from Jack B... | Thomas MacGreevy Papers |
| 1145 | UCC Special Collections & Archives | Box 8 | 1928-1966 | Books belonging to Nancy McCarthy including autograp... | Nancy McCarthy Collection |
| 18458 | UCC Special Collections & Archives | BL/P/J | 1966 | The collection contains 77 negatives and 3 contact s... | Anne James Photographic Collection |
| 1877 | UCD Archives | S6/43 (1-151) | 1727-1966 | The collection deals mainly with the property and le... | Hart-Synott Papers |
| 2082 | UCD Archives | P25 | 1891-1966 | The collection, mainly covering the period 1917-1927... | Peter Paul Galligan Papers |
| 1882 | UCD Special Collections | Kav/B/66 | 1966 | Tarry Flynn: Typescript copy of the play, script ada... | Kavanagh Collection |
| 24179 | Union Theological College | RH-1-224 | 1866-1966 | '100th Annual Report of the Presbyterian Orphan ... | |
| 18387 | University of Galway Archives | G44 | 1966-1974 | This collection spans the activities of the Language... | Language Freedom Movement |
| 1734 | Waterford City Archives | | 1962-1966 | Operations Book, 16 February 1962-14 May 1966. | Waterford City and County Infirmary |
| 1735 | Waterford City Archives | | 1966-1970 | Operations Book, 16 May 1966-23 April 1970. | Waterford City and County Infirmary |
| 4540 | Waterford City Archives | | 1958-1966 | Minute Book of Waterford City and County Infirmary, ... | Waterford City and County Infirmary |
| 4561 | Waterford City Archives | | 1958-1966 | Register of Extern Medical Patients, 6 December 1958... | Waterford City and County Infirmary |
| 4562 | Waterford City Archives | | 1966-1972 | Register of Extern Medical Patients, 4 February 1966... | Waterford City and County Infirmary |
| 4574 | Waterford City Archives | | 1953-1966 | Nursing Superintendents' Report Book, 24 November 19... | Waterford City and County Infirmary |
| 4593 | Waterford City Archives | | 1966-1969 | X-Ray Register, January 1966-February 1969. | Waterford City and County Infirmary |
| 4596 | Waterford City Archives | | 1963-1966 | X-Ray Book, January 1963-March 1966. | Waterford City and County Infirmary |
| 5912 | Waterford City Archives | AAC/07 | 1959-1966 | Visitors' Book Waterford Art Exhibitions. Records na... | Arts Advisory Committee |
| 23295 | Waterford City Archives | P30/ | 1957-1966 | 4: Folder of Application Forms for admittance, 1957-... | Michael Walsh Asylum |
| 23301 | Waterford City Archives | P30/ | 1932-1966 | 8: Receipts, expenditure, income and investments boo... | Michael Walsh Asylum |
| 23318 | Waterford City Archives | P30/ | 1905-1966 | 26: Miscellaneous items, letters unused admission fo... | Michael Walsh Asylum |
| 19206 | Westmeath County Archives Department | | 1966-1967 | Mullingar sewerage, 1966-1967 | Westmeath County Council |
| 19241 | Westmeath County Archives Department | | 1966-1968 | Westmeath County Council half-yearly abstract of ren... | Westmeath County Council |
| 19390 | Westmeath County Archives Department | | 1942-1966 | Athlone Urban District Council Workmen's Wages a... | Athlone Local Authority Records |
| 19391 | Westmeath County Archives Department | | 1966-1976 | Athlone Urban District Council Workmen's Wages a... | Athlone Local Authority Records |
| 19401 | Westmeath County Archives Department | | 1943-1966 | Athlone Urban District Council Artizan's Dwellin... | Athlone Local Authority Records |
| 19408 | Westmeath County Archives Department | | 1943-1966 | Athlone Urban District Council Artizan's Dwellin... | Athlone Local Authority Records |
| 19417 | Westmeath County Archives Department | | 1966-1967 | Athlone Urban District Council Rent Arrears Ledger:A... | Athlone Local Authority Records |
| 19452 | Westmeath County Archives Department | | 1966-1974 | Folder entitled 'Goldsmith Bi-Centenary' con... | Goldsmith Collection |