| 16166 | Birr Castle Archives | A-W | 1805-1806 | D/10/1-14: Letters between William Parsons and Lady ... | The Rosse Papers |
| 16187 | Birr Castle Archives | A-W | 1799
1806 | H/52: Bundle of letters between Lady Hawke and her d... | The Rosse Papers |
| 16164 | Birr Castle Archives | A-W | 1806-1842 | D/7/1-170: Letters to Sir William Parsons from his u... | The Rosse Papers |
| 5091 | Irish Architectural Archive | 97/84/Box 56 | 1656-1806 | Documents mainly relating to estates in Ballyshannon... | Castletown Papers |
| 20804 | Kilmore Diocesan Archives (RC) | Bishops,1625-1910 | 1806-1829 | Farrell O'Reilly, 1806-1829.15: Converts to the ... | Kilmore Diocesan Archives |
| 13055 | Limerick Museum | AQNO (1997.0190.28) | 1806 | Letter, wife of Lord Granard, (Lady Selina Frances R... | |
| 20116 | Meath Local Studies and Family History Department | Box DII/ | 1806 | 30 Lease of land at Painstown (Castletown) by Thomas... | Mountainstown Documents |
| 20159 | Meath Local Studies and Family History Department | Box C/ | 1806 | 16 Deed of sale Sheriff of Meath, and John Pollock 1... | Mountainstown Documents |
| 22895 | Methodist Historical Society of Ireland | | 1747-1749
1798
1806 | Archival box 5, contains, for example: Sermons by Re... | |
| 4960 | National Archives of Ireland | | 1798
1801
1806 | 1798 Rebellion Papers in the Quit Rent Office Collec... | Quit Rent Office |
| 8838 | National Archives of Ireland | SOC/3729/1-3 | 1806 | Edward Villiers Fitzgearld, Rockfield, near Limerick... | State of the Country Papers |
| 8839 | National Archives of Ireland | SOC/3913/ | 1806 | Copy of a letter from Jean Wilson, Kildrum, to her h... | State of the Country Papers |
| 11521 | National Archives of Ireland | | 1806 | Case of James Edmond Byrne Esquire, only brother of ... | Byrne Papers |
| 166 | National Library of Ireland | Ms18607 | 1806-1826
1816 | Nine autograph letters, several incomplete, from Jul... | Farnham Papers |
| 1497 | National Library of Ireland | Ms2069 | 1804-1806 | Includes two letters from Mary Ann Bulkley to her br... | |
| 1956 | National Library of Ireland | Ms4804 | 1806-1809 | A volume of critical book reviews by Mary Tighe, Apr... | Wicklow Papers |
| 2310 | National Library of Ireland | Ms4809 | 1805-1806 | Commonplace book of Caroline Hamilton of Hamwood, Co... | Wicklow Papers |
| 2321 | National Library of Ireland | Ms8326 | 1806-1808
1803
1954 | Typescript copies of the letters of Sarah Curran, Mr... | Sarah Curran papers |
| 2518 | National Library of Ireland | Ms4806 | 1805-1806 | Commonplace Book of [? Lady Eleanor Butler of Llango... | Wicklow Papers |
| 2618 | National Library of Ireland | Ms630 | 1779-1806 | Letters of Robert Stephen Fitzgerald to his mother, ... | |
| 2746 | National Library of Ireland | Ms20949 | 1806-1813 | Three letters to John D'Alton from his mother Eliza,... | D'Alton Papers |
| 2915 | National Library of Ireland | Ms8545 | 1775-1806 | Miscellaneous papers, 1775-1806. These include a ren... | D'Olier Papers |
| 2995 | National Library of Ireland | Ms9366 | 1671-1806 | Quit rent receipts of the Domville family in County ... | Domvile Papers |
| 3732 | National Library of Ireland | Ms12979 | 1806-1811 | Journal of payments by and to Sir Joshua Paul relati... | |
| 9107 | National Library of Ireland | Ms14498 | 1806-1810 | Journal of the journey to the court of the Emperor o... | Inchiquin Papers |
| 10118 | National Library of Ireland | Ms19501 | 1801-1806 | Tenant's Ledger of the estate in Counties Galway, Li... | Clonbrock Papers |
| 10675 | National Library of Ireland | Ms16927 | 1806-1818 | Pages from the minute book of Commissioners of Educa... | Dr Michael Quane Papers |
| 11008 | National Library of Ireland | Ms18607 | 1806-1826 | Nine autograph letters, some incomplete, from Julian... | Farnham Papers |
| 8037 | Public Record Office of Northern Ireland | T/1572/1 | 1806-1837 | Typescript extracts from Church of Ireland registers... | |
| 6633 | Public Record Office of Northern Ireland | D/1783 | c1806-1945 | 32 documents comprising of the family records of the... | |
| 7093 | Public Record Office of Northern Ireland | D/2762/ | 1806-1873 | Bundle of c.150 miscellaneous documents relating to ... | |
| 7768 | Public Record Office of Northern Ireland | MIC/316 | 1707-1738
1806 | Microfilmed copies of the family correspondence of t... | |
| 7933 | Public Record Office of Northern Ireland | T/1258/1-2 | 1630-1875
1806-1920 | Pedigree of the Rankin family of Devenish, County Fe... | |
| 8309 | Public Record Office of Northern Ireland | T/2370/1 | 1738-1806 | Genealogical notes on the Stewart family, Ballydrain... | |
| 8428 | Public Record Office of Northern Ireland | T/2660 | 1798-1806 | T/2660/2 Copy of a letter from Andrew Ferguson, Wat... | |
| 8566 | Public Record Office of Northern Ireland | T/3459/ | 1806-1825 | T/3459/D and T/3459/F Letters from and about the mis... | |
| 8590 | Public Record Office of Northern Ireland | T/402/62 | 1806 | Copy letters relating to patents in trust for Sarah ... | |
| 8612 | Public Record Office of Northern Ireland | T/521/1 | 1804-1806 | Copy of a list of passengers travelling from Ireland... | |
| 478 | Religious Society of Friends in Ireland Historical Library | Portfolio 6B | 1806-1896 | 1 Susannah Harvey to Thomas Pim, July 1896. 2 Abig... | Handlists/Portfolio |
| 878 | Religious Society of Friends in Ireland Historical Library | Mss Box 14 | 1806-1938 | Typescript of lecture on Quakerism given to Dun Laog... | Handlists: Mss Boxes, Pamphlets Boxes, etc. |
| 3568 | Religious Society of Friends in Ireland Historical Library | MM/XIIIZ2/Reel 29B | 1735-1806 | Record Book of Births, Marriages and Deaths of Vario... | |
| 10349 | Trinity College Dublin, Manuscripts and Archives Department | TCDMss10047/20 | c.1806-c.1850 | Correspondence of Helena Perceval, later Graves, fro... | Graves Papers |
| 10430 | Trinity College Dublin, Manuscripts and Archives Department | TCDMs10047/24 | 1799-1806 | Correspondence of Helena Perceval, later Graves, wit... | Graves Papers |
| 10484 | Trinity College Dublin, Manuscripts and Archives Department | TCDMs10315 | 1797-1806 | Account Book of the printing house of Mr [Richard Ca... | |
| 11539 | Trinity College Dublin, Manuscripts and Archives Department | Deposit | 1806-1807 | Illustrated diary and retrospectives of Dorothea Her... | |
| 11678 | Trinity College Dublin, Manuscripts and Archives Department | TDCMs5303-5305 | 1806-1825 | Incorporated Society for Promoting Protestant School... | Incorporated Society for Promoting Protestant Schools in Ireland |
| 5597 | UCD Archives | TU2 | 1806-1954 | Bakery and Food Workers Amalgamated Union. Diaries: ... | Irish Bakers', Confectioners' and Allied Workers' Union |