| 13157 | Armagh County Museum | 1941/57 | 1855 | Memorandum of Agreement between Portadown and Dungan... | |
| 16419 | Armagh Diocesan Archive (RC) | | 1855 | Letter of Sister M. de Sales, St Malachy's, Dund... | Most Reverend John Dixon Archive |
| 16420 | Armagh Diocesan Archive (RC) | | 1855 | Letter of Sister M. de Sales, St Malachy's, Dund... | Most Reverend John Dixon Archive |
| 16441 | Armagh Diocesan Archive (RC) | | 1855
1856
1861 | Miscellaneous:Letter of Ann Mullin, Ballygawly, addr... | Most Reverend John Dixon Archive |
| 19115 | Armagh Robinson Library | Volume 3 | 1855 | Papers on and a report of the Vaughan Charity School... | Primate J.G. Beresford Papers |
| 14613 | Belfast Central Library | | 1855-1867 | Z314 (5), Correspondence from John Mitchel to Henrie... | Francis Joseph Bigger Archive |
| 16206 | Birr Castle Archives | A-W | 1855 | J/22: Letters to 3rd Earl and Lady Rosse from Nassau... | The Rosse Papers |
| 4486 | Brother Allen Archive | Box 157 | 1820-1855 | 8 Letter to Mrs O'Connell, Cork, from her son, B... | Brother Allen Archival Collection |
| 16753 | Cashel, Ferns and Ossory Diocesan Archive (CoI) | | 1855-1870
1875-1881 | Parish of Killoughley, Annaghmere, Kings County, Rev... | Bolton Library Archive |
| 16817 | Cashel, Ferns and Ossory Diocesan Archive (CoI) | | 1817-1855 | 1 box folder marked 'the School', includes b... | Bolton Library Archive |
| 16859 | Cashel, Ferns and Ossory Diocesan Archive (CoI) | | 1855-1893 | Folder containing Clonoulty Vestry Minutes 1855-1893... | Bolton Library Archive |
| 4135 | Church of Ireland Centre | Ms684-685 | 1824-1855 | Ms 684 List of mistresses instructed in the Educatio... | Records of the Society for Promoting the Education of the Poor of Ireland |
| 17042 | Cloyne Diocesan Archive (RC) | Box F | 1855 | 1796.05/1/1855 Bishop W Keane's letter to priests, ... | Bishop W. Keane Papers |
| 12156 | Cloyne Diocesan Archive (RC) | Box F | 1854-1855 | 1795.07/32/1854 Statement of Anne Kiely relating to ... | Bishop T. Murphy |
| 17044 | Cloyne Diocesan Archive (RC) | Box F | 1855 | 1796.08/6/1855 Letter of Mr J Nagle to Bishop W Kea... | Bishop W. Keane Papers |
| 17045 | Cloyne Diocesan Archive (RC) | Box F | 1855 | 1796.08/7/1855 Marriage settlement of William McCar... | Bishop W. Keane Papers |
| 17046 | Cloyne Diocesan Archive (RC) | Box F | 1855 | 1796.07/14/1855 Letter from Mrs Ashlin, Dublin, to ... | Bishop W. Keane Papers |
| 17043 | Cloyne Diocesan Archive (RC) | Box F | 1855 | 1796.07/7/1855 Letter of Mrs Ashlin Dublin to Bisho... | Bishop W. Keane Papers |
| 22985 | Cork City and County Archives | U140/Class E/ | 1855 | Day81/12 Cork Blind Asylum, meetings, notices listin... | Dowden Papers |
| 24035 | Cork City and County Archives | U196 | 1845
1855 | Box 8 Contains legal documents, many of which relate... | Colthurst Papers |
| 14454 | Donegal County Archives | CH/SR/BV/B/ | 1855-1921 | Miscellaneous Records:CH/SR/BV/B/119. Inishowen Poor... | Donegal Poor Law Union Records |
| 18558 | Dublin Diocesan Archives (RC) | AB4 (File II, Nuns) | 1855-1856 | 1 January 1856, Female Orphan House, Harold's Cr... | Cullen Papers |
| 18557 | Dublin Diocesan Archives (RC) | AB4 (File II, Nuns) | 1855 | 15 January 1855, Frances Ball, Rathfarnham, to Archb... | Cullen Papers |
| 19930 | Erasmus Smith Schools Archives | | 1672-1855 | Letters concerning the wishes of Erasmus Smith, esqu... | Erasmus Smith Archives |
| 5074 | Irish Architectural Archive | 97/84/Box 21 | 1748-1855 | Bundles mainly containing leases relating to lands a... | Castletown Papers |
| 22251 | Irish Jesuit Archives | J27/ | 1855-1856 | 2 Letter from [ ], Belfast to Fr Russell concerning ... | Papers of Fr Matthew Russell, SJ (1834 - 1912) |
| 20871 | Kildare Local Studies, Genealogy and Archives Department | | 1855-1867 | Naas Town Commissioners, Minute Books: March 1855-No... | Naas Urban District Council |
| 3348 | Kilkenny Local Studies Department | BG57/AA | 1855-1968 | Rough Minute Books:1. September 1855-April 18572. Ma... | Castlecomer Poor Law Union |
| 20937 | King's Hospital School | 17-32 | 1839-1855 | 22 Committee of Accounts, 1839 - 1855. | King's Hospital Records |
| 20959 | King's Hospital School | 33-48 | 1669-1855 | 43A Benefactors, List of, 1669 - 1855. | King's Hospital Records |
| 21148 | King's Hospital School | 232-236A | 1836-1855
1877-1888 | 225b Rent Receipt Book, 1836-1855 Rental and Account... | King's Hospital Records |
| 21668 | Laois Local Studies | | 1853-1855 | Sale of the Estate of the Earl of Mornington in Encu... | |
| 439 | Longford Archives and Local Studies | | 1855-1925 | Minute Books:19 July 1855 - 29 December 185522 Novem... | Granard Poor Law Union |
| 5533 | Louth County Archives | BG/80/CC /196 | 1855-1859 | Dundalk Union Ledger, 1855 - 1859. | Dundalk Poor Law Union |
| 14144 | Louth County Archives | | 1855-1856 | Killany Tenants Rent Book, 1855-1856. | |
| 14516 | Mayo Local History Department | | 1855-1922 | Scrapbook of Newspaper Cuttings, 1855-1922 | Ballinrobe Rural District Council |
| 14553 | Mayo Local History Department | | 1855-1914 | Letter Books, 1855-1914 | Ballinrobe Poor Law Union |
| 5645 | Meath Local Studies and Family History Department | BG/99A/ | 1839 - 1855 | Minute Books:1 19 August 1839 - 29 August 18432 5 Se... | Kells Poor Law Union |
| 5657 | Meath Local Studies and Family History Department | BG/155/A/ | 1839- 1855 | Minute Books:1 July 1839 - March 18442 March 1844 - ... | Trim Poor Law Union |
| 5658 | Meath Local Studies and Family History Department | BG/155/A/ | 1855- 1864 | Minute Books:19 August 1855 - February 185621 August... | Trim Poor Law Union |
| 1854 | Monaghan County Library Genealogy and Local History Department | | 1855-1945 | Clones Urban District Council Minute Books: 15 Octob... | |
| 2111 | Monaghan County Museum | | 1855-1903 | Monaghan Urban District Council Rate Books, 1855-190... | |
| 21570 | Monaghan County Museum | | 1855-1903 | Rate Collection Books, Monaghan Urban, 1855-1903 | |
| 3273 | National Archives of Ireland | BG111AZC/ | 1851-1855 | Lismore Poor Law Union, Return of Elections to the B... | Lismore Poor Law Union |
| 4105 | National Archives of Ireland | VIA/8/2-3 | 1836-1855 | Lunatic Asylum Books, 1836-1855, 2 volumes | Privy Council Records |
| 4993 | National Archives of Ireland | 1045/5/4 | 1842-1855 | Unregistered forms of application for election of or... | Protestant Orphan Society |
| 8809 | National Archives of Ireland | 2/440/37-43 | 1838-1855 | Poor Law Commissioners' Letters to J Burke: 1838-184... | State Papers |
| 8810 | National Archives of Ireland | 2/440/444-447 | 1839-1855 | Poor Law Commissioners Papers: Reports to the Poor L... | State Papers |
| 8875 | National Archives of Ireland | 1045/5/6/8 | 1855-1859 | Register of Reports on the State of the Health and E... | Protestant Orphan Society |
| 15346 | National Archives of Ireland | 99/56/9/6 | 1855 | Papers relating to Co. Donegal. Settlement on the ma... | Family and estate records. 1611-1948 |
| 15500 | National Archives of Ireland | 999/113/6 | 1855 | Copy probate of the will of Anna Macartney, Dublin C... | Small Private Accessions |
| 21334 | National Gallery of Ireland Library | NGI/INST/1/1 | 1855-1970 | Minute Books, 1855-1970. Digitised items are availab... | Board Minutes of the National Gallery of Ireland |
| 2536 | National Library of Ireland | Ms4823 | c1855 | [? Original] song by W Vincent Wallace, entitled 'Wh... | |
| 2664 | National Library of Ireland | Ms8005 | 1855-1901 | Letters to Sir Charles Gavan Duffy, 1855-1901, from ... | Gavan Duffy Papers |
| 2750 | National Library of Ireland | Ms20955 | c1855-1865 | Letters to John D'Alton from his daughter Eliza (Sis... | D'Alton Papers |
| 2752 | National Library of Ireland | Ms20957 | c1855-1864 | Letters to John D'Alton from his niece Ellen Phillip... | D'Alton Papers |
| 2872 | National Library of Ireland | Ms329 | 1852-1855 | Typewritten copies of five letters of John Mitchell ... | |
| 2966 | National Library of Ireland | Ms8901 | 1791-1800
1855 | Rentals and other documents. These include rentals o... | |
| 2994 | National Library of Ireland | Ms9290 | 1855-1861 | Rentals of Lord Cloncurry's estates in County Limeri... | |
| 9138 | National Library of Ireland | Ms14801-14802 | 1855-1892 | Rent Ledger of the County Clare estates of the 14th ... | Inchiquin Papers |
| 9778 | National Library of Ireland | Ms18491 | 1855 | Ten letters from Robert McDonnell, mainly to his mot... | |
| 10097 | National Library of Ireland | Ms16389 | c1855 | Book of poems by Rose Eliza Benn, Roseville, Castlec... | |
| 10776 | National Library of Ireland | Ms19665 | c1855-1893 | Album of newscuttings and miscellaneous papers colle... | Clonbrock Papers |
| 10889 | National Library of Ireland | Ms21607 | [c1855-1858] | Letter from Lord Carlisle, the Lord Lieutenant, to M... | Hodson Papers |
| 11575 | National Library of Ireland | Ms20957 | c1855-64 | Fourteen letters to John D'Alton from his niece, Ell... | D'Alton Papers |
| 11595 | National Library of Ireland | Ms12378 | 1855 | Castlebar Poor Law Union Minute Book, 17 March 1855-... | |
| 11618 | National Library of Ireland | Ms12216 | 1854-1855 | Ballina Poor Law Union Minute Book, 9 September 1854... | |
| 11620 | National Library of Ireland | Ms12217 | 1855-1856 | Ballina Poor Law Union Minute Book, 4 August 1855-2 ... | |
| 11913 | National Library of Ireland | Ms12549-12558 | 1849-1855 | Killala Poor Law Union Minute Books: Ms12,549 6 Oct... | Killala Poor Law Union |
| 4820 | Newtown School, Waterford | Archive Room Safe | 1855-1870 | Joint Committee Minutes, 1855-1870. | |
| 18930 | Offaly Archives | OCL PTC40/3 | 1855 | 1 Drawing: 11 June 1855, drawing designs for lowerin... | Records of Parsonstown Town Commissioners |
| 6541 | Public Record Office of Northern Ireland | D/1503/3/5-8 | 1794-1855 | Legal papers and correspondence relating to the '... | Annesley Papers |
| 6548 | Public Record Office of Northern Ireland | D/1514/ | c.1564-1855 | D/1514/1/1/72/1 Petition of the widow Donnelly of Ki... | Hervey/Bruce Papers |
| 6600 | Public Record Office of Northern Ireland | D/1702 | 1855-1990 | This collection of 40 volumes and 2350 documents con... | Enniskillen Papers |
| 6714 | Public Record Office of Northern Ireland | D/1961 | 1841-1855 | This collection of 8 documents and 1 volume includes... | |
| 7286 | Public Record Office of Northern Ireland | D/3590/ | 1855-c.1905 | D/3590/H Box of c.300 family and personal letters to... | Higginson Papers |
| 7455 | Public Record Office of Northern Ireland | D/4088 | 1855-1878 | This collection of Hamilton of Brown Hall papers, in... | |
| 7729 | Public Record Office of Northern Ireland | LA/81/ | 1855-1923 | Local Authority records are closed for 30 years from... | Antrim Town Commissioners Records |
| 8065 | Public Record Office of Northern Ireland | T/1641 | c.1855 | 3 volumes of copies of the Encumbered Estates Court ... | |
| 8475 | Public Record Office of Northern Ireland | T/2772/ | 1855-1858 | This collection of papers has been copied from the o... | Beresford Papers |
| 8581 | Public Record Office of Northern Ireland | T/3755 | 1855 | Copy of a letter from Mary, Rosey and Ellen Fern[n] ... | |
| 8592 | Public Record Office of Northern Ireland | T/413/1-5 | 1852-1855 | Copy of a letter from John Mitchel, Tucaleechee Cove... | |
| 8614 | Public Record Office of Northern Ireland | T/529/ | 1849-1855 | T/529/18 Copy of a list of tenants for whom the land... | |
| 2283 | RCSI Heritage Collections | | 1855-1972 | Collection includes:Board Minute Books, 1878-1965 (9... | Royal City of Dublin Hospital, Baggott Street |
| 454 | Religious Society of Friends in Ireland Historical Library | Portfolio 2A | 1672-1855 | Testimonies, 1672-1855, 70 items. | Handlists/Portfolio |
| 1207 | Religious Society of Friends in Ireland Historical Library | P224 | 1855 | Red Book in Filing Cabinet 3 Wedding group of Samue... | Photographic Collections |
| 780 | Religious Society of Friends in Ireland Historical Library | QMII/H7-10 | 1837-1855 | Schools and Education: QMII/H7 Minutes of Munster P... | Munster Quarterly Meeting |
| 820 | Religious Society of Friends in Ireland Historical Library | QM1/H6-9 | 1800-1855 | Schools and Education: QM1/H6 Proceedings of the Co... | Leinster Quarterly Meetings |
| 824 | Religious Society of Friends in Ireland Historical Library | QMI/H21-28 | 1785-1855 | Schools and Education: QM1/H21 Provincial School Su... | Leinster Quarterly Meetings |
| 1282 | Religious Society of Friends in Ireland Historical Library | MMII/L1-4 | 1683-1855 | Wills and Inventories: MMII/L1 Wills and Inventorie... | Dublin Monthly Meeting |
| 23721 | Representative Church Body Library | | 1845-1855
1946-1964 | Parish Records of Ballinakill, County Waterford: Reg... | Waterford Cathedral |
| 22410 | Royal College of Physicians of Ireland | | 1835-1855 | Letter Book, 1835-1855. | Sir Patrick Dun's Hospital |
| 24933 | Royal Irish Academy of Music | | 1855-1858 | 1: 29 December 1855, 8 February 1856 - 13 April 1858... | |
| 12952 | St Columba's Hospital, Sligo | | 1855-1997 | Minute Books: 1. 06/01/1869 - 03/09/1873 2. 8/10/187... | |
| 6452 | Trinity College Dublin, Manuscripts and Archives Department | TCDMs5788 | 1855-1893 | Material relating to: The Endowed Schools' Commissio... | Incorporated Society for Promoting Protestant Schools in Ireland |
| 10123 | Trinity College Dublin, Manuscripts and Archives Department | TCDMss10247/1/415-434 | 1855-1902 | Letters of Henry Alfred Wynne of Collon House, inclu... | Wynne Family Papers |
| 10164 | Trinity College Dublin, Manuscripts and Archives Department | TCDMs3865 | 1844-1855 | Diaries of tours in Ireland and Germany by Frances E... | |
| 10210 | Trinity College Dublin, Manuscripts and Archives Department | TCDMs6429 | 1852-1855 | Diaries of Catherine Eliza Groves: 1 May 1852-9 Oct... | Groves Papers |
| 18460 | UCC Special Collections & Archives | BL/SC/FSM | 1855-1879 | 5 items, including:2. 10 Nov 1855. Ms lett... | Francis S. Mahony Collection |
| 22116 | University of Galway Archives | LE6 | 1855 | Copy on an indenture made 14 May 1855 between David ... | Wilson-Lynch Papers |
| 5934 | Waterford City Archives | LA1/7/A/ | 1855-1939 | Records of the Finance and Law Committee:1: 3 August... | Waterford Corporation Archives |
| 23321 | Waterford City Archives | P4/ | 1855-1913 | 3: Includes records of charges for the legal service... | The Penrose Family Collection |
| 9930 | Waterford County Archives | | 1831-1855 | Tithe Receipt Books, 1831-1855 and no date. There ar... | Lismore Castle Papers |
| 4304 | Westmeath County Archives Department | | 1855-1866 | Rental of the Estate of William Meade Smythe, 1855-1... | Smythe Papers |
| 19286 | Westmeath County Archives Department | | 1851-1855 | Athlone Poor Law Union Rough Minute Books:1 February... | Athlone Poor Law Union |
| 1475 | Wexford County Archive | | 1855-1940 | Financial Records of John E Redmond, Esq. June 1855-... | |