| 6984 | Armagh County Museum | 1976/119 | 1840 | Notebook, Charlotte Campbell, 1840, 248 pages, conta... | |
| 6985 | Armagh County Museum | 1976/133 | 1840 | Circular, 'Death fo James Stuart Esq., L.L.D.... | |
| 16414 | Armagh Diocesan Archive (RC) | | 1840 | Material relating to the Diocese of Raphoe, includes... | Primate McGettigan Archive |
| 19137 | Armagh Robinson Library | Volume 10 | 1840 | A list of annual contributions in support of scriptu... | Primate J.G. Beresford Papers |
| 8754 | Ballymena Central Library | U/A(LAR)362.5 | 1840-1851 | Larne Board of Guardian Minutes, copied from the Pub... | Larne Board of Guardian Records |
| 16171 | Birr Castle Archives | A-W | 1800-1840 | F/11: Notes by Sir Laurence Parsons on the history a... | The Rosse Papers |
| 16234 | Birr Castle Archives | A-W | 1840-1845 | O/30: 9 designs by Mary, Countess of Rosse, (? and o... | The Rosse Papers |
| 16878 | Cashel, Ferns and Ossory Diocesan Archive (CoI) | | 1668-1840 | Parish of St John's Cashel, alphabetical list of Bap... | Bolton Library Archive |
| 4236 | Church of Ireland Centre | Ms121 | 1837-1840 | Minutes of the Book Committees, 18 March 1837-3 Dece... | Records of the Society for Promoting the Education of the Poor of Ireland |
| 4260 | Church of Ireland Centre | Ms692 | 1840-1843 | Inspector's Reports of the Model School, 1840-18... | Records of the Society for Promoting the Education of the Poor of Ireland |
| 4287 | Church of Ireland Centre | Serial No158 | 1840 | General Correspondence, III:Lady F. Cole to Committe... | Records of the Society for Promoting the Education of the Poor of Ireland |
| 4288 | Church of Ireland Centre | Serial No160 | 1840 | General Correspondence, III:Mary Jackson and Son to ... | Records of the Society for Promoting the Education of the Poor of Ireland |
| 4289 | Church of Ireland Centre | Serial No164 | 1840 | General Correspondence, III: Lady Dunraven to J. Top... | Records of the Society for Promoting the Education of the Poor of Ireland |
| 4293 | Church of Ireland Centre | Box 10 | 1818-1840 | Lithographed and Printed Papers, 1818-1840:Serial No... | Records of the Society for Promoting the Education of the Poor of Ireland |
| 19020 | Church of Ireland Centre | Box 36 | 1840 | Model School:Mod. 75 - Letter to Mrs Duncan from Ano... | Records of the Society for Promoting the Education of the Poor of Ireland |
| 19029 | Church of Ireland Centre | Box 36 | 1840 | Model School:Mod. 100 - 'School Assisted by the ... | Records of the Society for Promoting the Education of the Poor of Ireland |
| 17000 | Cloyne Diocesan Archive (RC) | Box B | 1840 | 1796.20/2/1840 They are prepared for reception of M... | Bishop W. Keane Papers |
| 17017 | Cloyne Diocesan Archive (RC) | | 1840 | 1793.05 2/1840 letter Bishop B Crotty, Cove, to Rev... | Bartholomew Crotty Papers |
| 17161 | Cloyne Diocesan Archive (RC) | Box X | 1840 | 1792.08/1/1840 Letter from J. Mullane, Liverpool, to... | Revd. Denis Collins |
| 17162 | Cloyne Diocesan Archive (RC) | Box X | 1840 | 1792.08/2/1840 Statement of intent relating to educ... | Revd. Denis Collins |
| 12999 | Cork City and County Archives | YTR/B | 1610-1840 | Youghal Corporation Records, 1610-1659; 1666-87; 169... | Council Books of the Corporation of Youghal |
| 13104 | Cork City and County Archives | B500/ | 1840-1957 | A list is available in the Archives. 13/2 Account B... | Business Records of John Dowden and Company, Cork |
| 22929 | Delany Archive | Box Bp/10 File FH/1840/ | 1840 | 14: 16 June 1840 Mrs Mary Price, Westfield Farm, to ... | Papers of Dr Francis Haly, Bishop of Kildare & Leighlin |
| 1675 | Donegal County Archives | CH/BV/D/3 | 1840-1857
1897-1950 | Miscellaneous Donegal Records:112. Compulsory Purcha... | |
| 3405 | Donegal County Archives | CH/BG/1/; CH/BG/2/ | 1840-1922 | Minute Books (Digitised):Ballyshannon Board of Guard... | Ballyshannon Poor Law Union |
| 19866 | Erasmus Smith Schools Archives | | 1672-1840 | Leases for Trust estates in County Limerick; 2 boxes... | Erasmus Smith Archives |
| 5096 | Irish Architectural Archive | 97/84/Box 62 | 1821-1840 | Account Book of Edward Conolly, 1821-1840, 1 item. | Castletown Papers |
| 5110 | Irish Architectural Archive | 97/84/Box 78 | 1694-1840 | Leases, letters and legal documents relating to vari... | Castletown Papers |
| 6255 | Irish Room, County Hall, Coleraine (Closed) | | 1840s-1973 | Bound photocopied selection of minutes from Colerain... | Irish Room |
| 21729 | Kerry Diocesan Archives (RC) | E87 | 1838-1840
1827
1832 | Memoranda regarding hospital, 1827, 1832, 1838-1840. | Bishop Cornelius Egan, 1825 - 1856 |
| 2049 | Kerry Local Studies and Archives Department | BG/154/A/ | 1840-1853 | Minute Books:1. May 1840 - March 1845 (First meeting... | Tralee Poor Law Union |
| 2042 | Kerry Local Studies and Archives Department | BG/100/A/ | 1840-1921 | Board of Guardians, Kenmare Union, Minute Books:1. D... | Kenmare Poor Law Union |
| 2044 | Kerry Local Studies and Archives Department | BG/104/A/ | 1840-1922 | Minute Books:1. December 1840 - November 18452. Dece... | Killarney Poor Law Union |
| 2048 | Kerry Local Studies and Archives Department | BG/112/A/ | 1840-1922 | Minute Books:1. May 1840 - November 18452. November ... | Listowel Poor Law Union |
| 21006 | King's Hospital School | 83-99 | 1840-1844 | 90 Agents Accounts, King's Hospital, 1840 - 1844. | King's Hospital Records |
| 21193 | King's Hospital School | 254-281 | 1840 | 261 Governors, List of, 1840. | King's Hospital Records |
| 1833 | Leitrim Local Studies Department | Reel No 3 | 1840-1988 | 1. Parish: Oughteragh, School: Ballinamore Boys, 193... | School Registers |
| 112 | Limerick Archives | P12 | 1840-1980 | Cannock papers: company minutes, 1877-1929 (on micro... | Cannock Papers |
| 6983 | Limerick Museum | AQNO (0000.1893) | 1839-1840 | Poster. Account of the Governors and Governesses of ... | |
| 6986 | Limerick Museum | AQNO (0000.1894) | 1840-1841 | Poster. Account of the Governors and Governesses of ... | |
| 13846 | Limerick Museum | AQNO (0000.4451) | c.1840 | Photograph. Glass slide. Object. Print, Wellesley Br... | |
| 18583 | Maynooth University and St Patrick's College, Maynooth | PP/13 | 1720-1840 | This collection includes leases, mortgages, tenancie... | The Burrowes Archive |
| 14556 | Mayo Local History Department | | 1840-1940 | Includes images from Mayo; for example, a photo of a... | Sexton Photographic Collection |
| 22852 | Methodist Historical Society of Ireland | | 1840-1845 | Dublin Circuit Plan: 1840-1845 | |
| 13148 | Monaghan County Library Genealogy and Local History Department | | 1852-1853, 1840-1843 | Photocopy of the manuscript Rent Book of the Newblis... | |
| 707 | National Archives of Ireland | BG/78/ | 1840-1856 | Registers of Admission and Discharge:G1 5 May 1840G2... | North Dublin Poor Law Union and Rural District Council |
| 8897 | National Archives of Ireland | M6933/10 | 1821
1822
1839
1840
1841 | Bundle of rentals of various portions of the Blake e... | Ballyglunin Papers |
| 8943 | National Archives of Ireland | M6178/79 | 1840 | Papers relating to the Corranerary Estate of William... | Greville Estate Papers |
| 11507 | National Archives of Ireland | | 1831-1840 | Notebook containing accounts for living in Italy, al... | Byrne Papers |
| 15512 | National Archives of Ireland | 999/128/19 | 1840 | Lease for 21 years by the Right Honourable Lord John... | Small Private Accessions |
| 165 | National Library of Ireland | Ms18597 | 1839-1840 | Two letters of Maria Edgeworth, one to Miss Crampton... | |
| 963 | National Library of Ireland | Ms11350 | 1800-1840 | Letters of General Sir F Trench to his parents, earl... | Domvile Papers |
| 1018 | National Library of Ireland | Ms13093 | 1840-1853 | Photostats of eight letters of Mrs Anne Pilkington, ... | |
| 1485 | National Library of Ireland | Ms1557 | 1834-1840 | Description: School Attendance book of the Children ... | |
| 2017 | National Library of Ireland | Ms8185 | c1840-50 | Letters, accounts and other papers relating to the C... | |
| 2449 | National Library of Ireland | Mss3579-3580 | 1838-1840 | Two Journals of Mrs Francis Howard of Swords, June 1... | Wicklow Papers |
| 2497 | National Library of Ireland | P8423/Ms8221 | 1830
1840 | Petition, 1840, to the Secretary of State for the Co... | |
| 2540 | National Library of Ireland | P1098/N1016 | c1840 | Includes many letters to Elizabeth Cole, c1840. Micr... | Ballitore Papers |
| 2633 | National Library of Ireland | Ms5757 | 1840-1854 | Letters to Charles Gavan Duffy from peopole prominen... | |
| 2704 | National Library of Ireland | Ms10594 | 1832-1840 | Correspondence of Mrs Ann Carolan of Dublin, concern... | |
| 2904 | National Library of Ireland | Ms8599 | 1840-1881 | Miscellaneous papers relating to the Earl of Bantry'... | Earl of Bantry Papers |
| 2918 | National Library of Ireland | Ms8630 | 1749-1840 | Documents and letters relating to the Roche family o... | Roche Papers |
| 3006 | National Library of Ireland | Ms9472 | 1840-1848 | Rent ledger of tenants at Kilmacumpsy and Corradrehi... | Pakenham-Mahon Papers |
| 3593 | National Library of Ireland | Ms12152 | 1840-1860 | Details of rent abatements on properties which are p... | |
| 3608 | National Library of Ireland | Ms13112 | 1840-1845 | Thirty letters from Aubrey de Vere to Harriet Thomp... | De Vere Papers |
| 3615 | National Library of Ireland | Ms13125 | 1840-1901 | Letters to Aubrey de Vere in alphabetical order of c... | De Vere Papers |
| 3616 | National Library of Ireland | Ms13127 | 1840-1901 | Letters to Aubrey de Vere in alphabetical order of s... | De Vere Papers |
| 2369 | National Library of Ireland | Ms8003 (1-11) | c1780-1840 | Letters and papers of the Leadbeater, Shackleton and... | Ballitore Papers |
| 6900 | National Library of Ireland | Ms18893 | 1840-1854 | Letters to John Macnamara from Mary Frances Woulfe, ... | Stacpoole Kenny Papers |
| 6906 | National Library of Ireland | Ms18905 | 1840 | Letter of Michael Stacpoole, Milford [County Limeri... | Stacpoole Kenny Papers |
| 9024 | National Library of Ireland | Ms13748(8) | c1817-1840 | Ten letters from Lady Gertrude Fitzpatrick to Richar... | Fitzpatrick Papers |
| 9027 | National Library of Ireland | Ms13751(9) | 1840 | Nineteen letters to Richard Wilson Fitzpatrick from ... | Fitzpatrick Papers |
| 9074 | National Library of Ireland | Ms14182 | 1833-1840 | Names, addresses and benefactions of persons in rece... | Prior-Wandesforde Papers |
| 9161 | National Library of Ireland | Ms15026 | 1840-1849 | Letters to Thomas Wyse, MP, 1840-1849, correspondent... | Wyse Papers |
| 9296 | National Library of Ireland | Ms23405 | 1840-1879 | Copy of the bible, printed Dublin, 1847, containing ... | MacIomhair Papers |
| 9586 | National Library of Ireland | Ms29792(1-13) | 1828-1840 | Rentals, Leitrim estate, 1828-1840. There are 13 fol... | Bessborough Papers |
| 9592 | National Library of Ireland | Ms29805(15) | 1828-1840 | Bills for assisted emigration to Newfoundland, USA a... | Bessborough Papers |
| 9727 | National Library of Ireland | Ms18237 | 1840-1848 | Accounts of payments of rent by tenants in Aughafan,... | Dimond Papers |
| 10077 | National Library of Ireland | Ms16136 | 1840-1847 | Journal of Thomas Edwards, Carlow, sometime emigrati... | |
| 10102 | National Library of Ireland | Ms16409 | 1840-1843 | Rent Ledger of the Mullingar area, County Westmeath,... | Hodson Papers |
| 10671 | National Library of Ireland | Ms16918 | 1813-1840 | Minute Book of Commissioners of Education in Ireland... | Dr Michael Quane Papers |
| 10720 | National Library of Ireland | Mss19585-19608 | 1827-1840 | Rentals and accounts of the estates of Robert Dillon... | Clonbrock Papers |
| 10721 | National Library of Ireland | Mss19609-19645 | 1840-1892 | Rentals and accounts of the estate of Robert Dillon,... | Clonbrock Papers |
| 10748 | National Library of Ireland | Ms19874 | 1830-1840 | Rent Book, estate of Thomas Studdert, Bunratty, Coun... | Studdert Papers |
| 10752 | National Library of Ireland | Ms19917-19920 | c.1840-1880 | Two Registers of tenants, estate of Duke of Leinster... | Leinster Papers |
| 10827 | National Library of Ireland | Ms20777 | c1840-1860 | Letters and miscellaneous receipts relating to the D... | Crofton Papers |
| 10888 | National Library of Ireland | Ms21604 | 1840 | Draft of a petition of Henrietta Arnauld, Lismore, t... | Hodson Papers |
| 11585 | National Library of Ireland | Ms12705 | 1840-1847 | Westport Poor Law Union Account Ledger, October 1840... | |
| 11587 | National Library of Ireland | Ms12370 | 1840-1843 | Castlebar Poor Law Union Rough Minute Book, 23 Janua... | |
| 11588 | National Library of Ireland | Ms12371 | 1840-1843 | Castlebar Poor Law Union Minute Book, 23 January 184... | |
| 18886 | Offaly Archives | OCL GJ1/3 | 1836-1840
1854-1859 | Coroner's Report Books | Records of King's County Grand Jury |
| 18989 | Offaly Archives | OCL P22 | 1834-1840 | Manuscript rent roll for the Banagher Estate, King's... | Rental of Banagher Estate |
| 6280 | Public Record Office of Northern Ireland | BG/14/ | 1840-1950 | All board of guardian records are closed for 100 yea... | Enniskillen Board of Guardian Records |
| 6281 | Public Record Office of Northern Ireland | BG/15/ | 1840-1948 | All board of guardian records are closed for 100 yea... | Irvinestown Board of Guardian Records |
| 6283 | Public Record Office of Northern Ireland | BG/17/ | 1840-1948 | All board of guardian records are closed for 100 yea... | Larne Board of Guardian Records |
| 6299 | Public Record Office of Northern Ireland | BG/5/ | 1840-1961 | Ballymoney Board of Guardians Minute Books: BG/5/A/1... | Ballymoney Board of Guardians |
| 8099 | Public Record Office of Northern Ireland | T/1739 | 1840 | Copy of a subscription list for the erection of a sc... | |
| 6326 | Public Record Office of Northern Ireland | D/1044 | 1717-c1840 | Correspondence and papers of the Greer family of Dun... | Greer Papers |
| 6341 | Public Record Office of Northern Ireland | D/3227 | 1840-1875 | 8 emigrant letters from members of the Cole family, ... | |
| 6385 | Public Record Office of Northern Ireland | T/1801/6 | 1840 | Copy of a letter from Eliza Browne, Belfast to Maria... | |
| 6790 | Public Record Office of Northern Ireland | D/2259 | c.1835-1840 | c.600 documents comprising of the papers of the 2nd ... | |
| 8150 | Public Record Office of Northern Ireland | T/1931/9 | 1840-1875
1884 | Genealogical notes on the Russell family, Newtownard... | |
| 8219 | Public Record Office of Northern Ireland | T/2103/1 | 1840-1963 | Pedigree of Thomas McComb, Larne, c.1840-1963. The d... | |
| 8461 | Public Record Office of Northern Ireland | T/2746/1A-B | 1840 | 2 copies of a list of passengers on board the ship '... | |
| 7027 | Public Record Office of Northern Ireland | D/2585/ | c.1840-1969 | D/2585/20/1 Verses written by Susann Hogg in memory ... | Strain Papers |
| 7049 | Public Record Office of Northern Ireland | D/2648 | c.1840-1970 | c.100 volumes and 450 documents relating to the Ulst... | |
| 7266 | Public Record Office of Northern Ireland | D/3539/1-2 | 1826-1840 | Household Account Book, 1826-1830 and Recipe Book of... | Thomson of Jennymount Papers |
| 7528 | Public Record Office of Northern Ireland | D/729/ | 1786-1840s | D/729/20-22 Letters from Hamilton Young, general mer... | Drennan-Duffin Papers |
| 7769 | Public Record Office of Northern Ireland | MIC/32 | 1840-c.1843 | Draft letter from Mary Cunningham, Glenwood, [reject... | Cunningham (Belfast) Papers |
| 8036 | Public Record Office of Northern Ireland | T/1571/1 | c.1840-1844 | Copy of a subscription list relating to a new church... | |
| 8312 | Public Record Office of Northern Ireland | T/2383/ | 1832-1840 | Print-outs from microfilm copies of the Ordnance Sur... | |
| 8538 | Public Record Office of Northern Ireland | T/3034/1-2 | 1840-1841 | Copies of two letters from Elizabeth McCleland, Dunr... | |
| 8573 | Public Record Office of Northern Ireland | T/3606 | c.1840-1880 | T/3606/3 Copy of a photograph of Mrs McCartney, who ... | |
| 8701 | Public Record Office of Northern Ireland | T/852/1 | c1840-c1848 | Copy of the notebook of the late Canon Grainger, Bel... | |
| 8729 | Public Record Office of Northern Ireland | T/956/118 | c.1835-1840 | Map of Mrs May's property, York Road, Belfast, c... | L'Estrange and Brett Solicitors Papers |
| 2270 | RCSI Heritage Collections | LOAn/3/4 | 1840-1875 | Medical Commonplace Book, of Dublin origin, author u... | |
| 547 | Religious Society of Friends in Ireland Historical Library | Portfolio 32 | 1837-1840 | 6 Certificate of Removal, Amelia Wright from Mountm... | Handlists/Portfolio |
| 578 | Religious Society of Friends in Ireland Historical Library | YM/B7 | 1785-1840 | Women's Meeting: Minutes and names of representative... | Yearly Meetings |
| 1215 | Religious Society of Friends in Ireland Historical Library | P67 | 1840-1950 | Family Groups: Family Group Photograph. Hannah, nee ... | Photographic Collections |
| 1338 | Religious Society of Friends in Ireland Historical Library | | 1840 | Temperance: Pledge, Father Matthew, signed by Cather... | Museum Collection |
| 548 | Religious Society of Friends in Ireland Historical Library | Portfolio 33 | 1840-1841 | 1 Certificate of Removal, Anne Grubb from Edenderry... | Handlists/Portfolio |
| 822 | Religious Society of Friends in Ireland Historical Library | QM1/H11-19 | 1840-1920 | Schools and Education: QM1/H11 Minutes of Sub-Commi... | Leinster Quarterly Meetings |
| 843 | Religious Society of Friends in Ireland Historical Library | QMI/H58-64 | 1840-1921 | Schools and Education: QMI/H58 Camden School Minute... | Leinster Quarterly Meetings |
| 844 | Religious Society of Friends in Ireland Historical Library | QMI/H65-69 | 1804-1840 | Schools and Education: QMI/H65 Proceedings of the C... | Leinster Quarterly Meetings |
| 845 | Religious Society of Friends in Ireland Historical Library | QMI/H70-72 | 1840-1884 | Schools and Education: QMI/H70 Minutes of General C... | Leinster Quarterly Meetings |
| 2179 | Representative Church Body Library | Ms527 | 1840-1921 | Minutes, 1860-1929; accounts, 1857-1942; register o... | Kerry Protestant Orphan Society |
| 22080 | Representative Church Body Library | B5 | 1696-1840 | Innishannon Parish, Register of Baptism, February 16... | St Fin Barre's Cathedral Cork Archive |
| 19795 | Tipperary Studies | | 1840-1856 | Rate Books:Abington: July 1852 November 1852 July 18... | Nenagh Poor Law Union |
| 6890 | Trinity College Dublin, Manuscripts and Archives Department | TCDMs10409 | 1773-1840 | Commonplace Book of the Pearson family of Clondalkin... | |
| 10194 | Trinity College Dublin, Manuscripts and Archives Department | TCDMs10409 | 1773-1840 | Commonplace Book of Grace Pearson and family, Clonda... | |
| 10271 | Trinity College Dublin, Manuscripts and Archives Department | TCDMs5089a | 1836, 1838, 1840, no date | Correspondence of the Honourable Grace O'Brien, 1836... | |
| 11154 | Trinity College Dublin, Manuscripts and Archives Department | TCDMs5089a | 1836-1840 | Correspondence of Elinor de Vere O'Brien with her si... | O'Brien Family |
| 11223 | Trinity College Dublin, Manuscripts and Archives Department | P31/4/1-4 | 1837-1840 | H Gore, Kilkenny Tenants Accounts, 1837-1840. | Courtown Papers |
| 24155 | Union Theological College | | 1840-1999 | General Assembly of the Presbyterian Church of Irel... | |
| 6967 | University of Galway Archives | LE1 | 1833-1840 | Account Book of John Carson, agent for Lord Crofton,... | Crofton Estate |
| 6972 | University of Galway Archives | LE2 | 1834-1840 | Account Book of John Carson, agent for the Rev. Will... | Cleaver Estates in Co. Roscommon |
| 18599 | University of Limerick Special Collections and Archives | P/1 (Section D) | 1840-1895 | Section D: Desmond John Edmund FitzGerald (1840-1895... | The Glin Papers |
| 13103 | Waterford and Lismore Diocesan Archives (RC) | | 1840-1849 | Contents of box marked 1840-1849 includes: 1 Will o... | |
| 1465 | Wexford County Archive | | 1840-1919 | WX/BG 94/1/1 24 January 1840 – 14 January... | Gorey Poor Law Union |
| 1476 | Wexford County Archive | WX/BG | 1840-1922 | WX/BG 162/1/1 1 August 1840 – 29 July 184... | Wexford Poor Law Union |
| 1250 | Wexford County Archive | BG/87/1/ | 1840-1920 | WX/BG 87/1/1 – WX/BG 87/1/10 20 Mar 1840 ... | Enniscorthy Poor Law Union Records |
| 1468 | Wexford County Archive | | 1840-1913 | 1. Gorey Board of Guardians Minute Book 14 September... | Wexford Poor Law Union Records (Miscellaneous) |