There are a significant number of manuscript collections which offer invaluable resources in the fields of Irish culture and language studies.
- Arnold Bax Collection
- Beranger Watercolours Collection
- Cartlann na gCanúintí
- Dubhaltach Mac Firbishigh’s Great Book of Irish Genealogies
- Patrick Ferriter Manuscripts
- William Lover Papers
- Riobard Mac Góráin Collection
- Henry Morris Manuscripts
- Henry Morris Additional Manuscripts
- Henry Morris Papers
- Henry Morris Correspondence
- Irish Academy of Letters
- Eugene O’Curry Manuscripts
- Annie O'Donnell Letters
- John O’Donovan/William Reeves Correspondence
- Colm Ó Lochlainn Letters
- Colm Ó Lochlainn Manuscripts
- UCD Library Building Papers
- UCD Additional Irish Manuscripts
- UCD Manuscripts
- Sture Ureland Collection
- William Wilde Manuscript