| 16391 | Armagh Diocesan Archive (RC) | | 1801 | Letters of Most Reverend Dr Reilly, Archbishop of Ar... | Most Reverend Richard Reilly Archive |
| 16173 | Birr Castle Archives | A-W | 1788
1797
1801 | H/37: Letters to Cassandra, wife of 2nd Lord Hawke f... | The Rosse Papers |
| 16181 | Birr Castle Archives | A-W | 1786-1788
1795-1801 | H/45-46: Letters to Lady Hawke from Elizabeth Leigh,... | The Rosse Papers |
| 16186 | Birr Castle Archives | A-W | 1798-1801 | H/51: Includes a draft letter from Lady Hawke to her... | The Rosse Papers |
| 16170 | Birr Castle Archives | A-W | 1801-1810 | E/33/1-47: Correspondence of the 2nd Earl of Rosse, ... | The Rosse Papers |
| 16190 | Birr Castle Archives | A-W | 1797-1801
1789 | H/55: Letters to Lady Hawke from Mrs Anne Wolley, Yo... | The Rosse Papers |
| 16904 | Cashel, Ferns and Ossory Diocesan Archive (CoI) | | 1801-1891 | Rental Books from various parishes, c.80, 1801-1891. | Bolton Library Archive |
| 3696 | Cork City and County Archives | U225 | 1756-1801 | Apprentice Indentures Enrolling book, 17 January 175... | |
| 8780 | Irish Dominican Congregation Archives | A9 | 1782-1801 | Channel Row: Account book, number 7, 1772 July - 180... | Dominican Archives, Cabra |
| 20921 | King's Hospital School | 1-16a | 1779-1801 | 7 Board Minute Book, 1779-1801. | King's Hospital Records |
| 21041 | King's Hospital School | 116-130 | 1801-1810 | 123 Cash Book, 1801 - 1810. | King's Hospital Records |
| 13061 | Limerick Museum | AQNO (0000.1683) | 1801 | Letter, T. and E. Mason to Shepard Frinch? Carrick a... | |
| 5000 | Maynooth University and St Patrick's College, Maynooth | Ms Murphy 51 | 1786-1801 | Red Branch and other tales, 18th century Munster poe... | |
| 20085 | Meath Local Studies and Family History Department | Box DI/ | 1801 | 15 Deed between Thomas Bligh, Brittas and Anthony Ca... | Mountainstown Documents |
| 20087 | Meath Local Studies and Family History Department | Box DI/ | 1801 | 17a Lease of land at Boynagh to John Clifford by Tho... | Mountainstown Documents |
| 20148 | Meath Local Studies and Family History Department | Box C/ | 1801 | 6 Lease between William Corbally (Drakestown) and Jo... | Mountainstown Documents |
| 20180 | Meath Local Studies and Family History Department | Box G/ | 1801 | 1 Deed between Thomas Bligh Brittas and Philip McNal... | Mountainstown Documents |
| 21296 | Meath Local Studies and Family History Department | Box DII/ | 1801 | 46 Lease of land at Cornicarrow by Thomas Bligh, Bri... | Mountainstown Documents |
| 3946 | National Archives of Ireland | Carton 620/60 | 1801 | 40 Petition of Teresa Magrath, widow of the late Li... | Rebellion Papers |
| 4067 | National Archives of Ireland | | 1801 | Anne, Lady Ormonde, to Thomas Kemmis asking for advi... | Frazer Manuscripts |
| 4960 | National Archives of Ireland | | 1798
1801
1806 | 1798 Rebellion Papers in the Quit Rent Office Collec... | Quit Rent Office |
| 4966 | National Archives of Ireland | | 1798
1801 | 1798 Rebellion Papers in the Quit Rent Office Collec... | Quit Rent Office |
| 11527 | National Archives of Ireland | | 1801-1889 | Includes correspondence to Mrs C.B. Byrne relating t... | Byrne Papers |
| 914 | National Library of Ireland | Ms5245 | 1684-1801 | Rental receipts of the Pratt family and corresponden... | |
| 1507 | National Library of Ireland | Ms2048 | 1742-1801 | Photocopy of registry of births, marriages and death... | |
| 2982 | National Library of Ireland | Ms9139 | 1801 | Photocopy of a recovery relating to lands at Barry's... | |
| 3016 | National Library of Ireland | Ms9592 | 1801 | List of subscribers, rules, lists of students and li... | Townley Hall Papers |
| 3518 | National Library of Ireland | Ms10114 | 1716-1801 | Letters to, or by, members of the Sandford family 17... | Pakenham-Mahon Papers |
| 3605 | National Library of Ireland | Mss12720- 12723 | 1746-1801 | Rentals of the estates of the Earl of Drogheda, Coun... | Drogheda Papers |
| 3623 | National Library of Ireland | Ms12789 | 1801 | Rent Roll of the Earl of Leitrim's estate in the Bar... | Leitrim Papers |
| 9006 | National Library of Ireland | Ms13650 | 1801-1814 | Letters to Daniel O'Connel from Mary O'Connell, Janu... | O'Connell Papers |
| 9165 | National Library of Ireland | Ms13876 | 1790-1801 | Nine letters to Thomas Walton, Kinsale County Cork, ... | |
| 9308 | National Library of Ireland | Ms23463 | 1800-1801 | Domestic and Personal Account Book [of Charlotte Vis... | Doneraile Papers |
| 10118 | National Library of Ireland | Ms19501 | 1801-1806 | Tenant's Ledger of the estate in Counties Galway, Li... | Clonbrock Papers |
| 10764 | National Library of Ireland | Ms20296 | c1801 | Twelve letters to Charles O'Hara, the younger and to... | O'Hara Papers |
| 19099 | Newry City Library | Q41.65.8 | 1801-1821
1911 | 14 volumes of bound, typescript and handwritten pape... | The Crossle Papers |
| 5457 | Newtown School, Waterford | | 1801-1869 | Penmanship: 1801-1853 1840-1850 1842-1850 1844-1869. | |
| 6620 | Public Record Office of Northern Ireland | D/1751 | 1801-1959 | This collection of c50 documents includes genealogic... | |
| 6677 | Public Record Office of Northern Ireland | D/1889/ | 1801-1924 | This collection of c.800 volumes, documents and cutt... | Wallace Papers |
| 7903 | Public Record Office of Northern Ireland | T/1182/1 | 1801-1826 | Copy of the Vestry Book, Derrykeighan parish, County... | |
| 6718 | Public Record Office of Northern Ireland | D/1968 | 1801-1953 | 30 documents comprising of title deeds, marriage set... | |
| 7044 | Public Record Office of Northern Ireland | D/2633 | 1801-1938 | c.90 documents comprising of title deeds, genealogic... | |
| 7508 | Public Record Office of Northern Ireland | D/607/I-L | 1801-1836 | Correspondence of the Dowager Marchioness of Downshi... | Downshire Papers |
| 7549 | Public Record Office of Northern Ireland | D/955/ | 1768-1801 | D/955/11-16 Letters from Hester Habersham, nee Wylly... | |
| 7778 | Public Record Office of Northern Ireland | MIC/432 | 1771-1801 | Microfilmed copy of a Wives' Certificate Book of the... | |
| 8046 | Public Record Office of Northern Ireland | T/1592/2-18 | 1801-1810 | This collection of c.14 documents includes emigrant ... | |
| 8386 | Public Record Office of Northern Ireland | T/2581 | 1801-1900s | This collection of 81 documents includes, for exampl... | |
| 8459 | Public Record Office of Northern Ireland | T/2738/ | 1801-1830 | T/2738/1 Copy of a farm account book kept by Mary Do... | |
| 8598 | Public Record Office of Northern Ireland | T/439 | 1801-1882 | Copy extracts from the letters of the Lynn, Lawther ... | |
| 479 | Religious Society of Friends in Ireland Historical Library | Portfolio 6C | 1688-1801 | 4 From Carlow Men's Meeting regarding Elizabeth Bar... | Handlists/Portfolio |
| 772 | Religious Society of Friends in Ireland Historical Library | QMIII/B/Reel 4 | 1792-1801 | Women's Meeting: Minutes of Ulster Quarterly Women's... | Ulster Quarterly Meetings |
| 773 | Religious Society of Friends in Ireland Historical Library | QMIII/B2/Reel4 | 1794-1801 | Women's Meeting: Minutes of Ulster Quarterly Women's... | Ulster Quarterly Meetings |
| 816 | Religious Society of Friends in Ireland Historical Library | QM1/H2 | 1704-1801 | Schools and Education: Proceedings of the Committee ... | Leinster Quarterly Meetings |
| 877 | Religious Society of Friends in Ireland Historical Library | Mss Box 13 | 1801-1901 | Cork and Youghal Papers: Old Account Book containing... | Handlists: Mss Boxes, Pamphlets Boxes, etc. |
| 1440 | Religious Society of Friends in Ireland Historical Library | Portfolio 37C | 1801-1887 | 3 Epistle from Philadelphia Women's Yearly Meeting ... | Handlists/Portfolio |
| 3556 | Religious Society of Friends in Ireland Historical Library | LBM/5/28/Reel 23 | 1801-1841 | Testimonies Acknowledging Misconduct, Lisburn Monthl... | |
| 3559 | Religious Society of Friends in Ireland Historical Library | LBM/5/34/Reel 23 | 1801-1809 | Letters of Resignation from the Society of Friends, ... | |
| 11686 | Trinity College Dublin, Manuscripts and Archives Department | TCDMss5582-5596 | 1801-1890 | Incorporated Society for Promoting Protestant School... | Incorporated Society for Promoting Protestant Schools in Ireland |
| 5926 | Waterford City Archives | LA1/1/A/ | 1669-1801 | Council Records, Minute Books: 6: 29 September 1669 ... | Waterford Corporation Archives |