Some letters of John O'Donovan, written, mostly, to Henthorn Todd, on points of Irish history and scholarship.

Míreanna comhchosúla

• The Martyrology of Donegal: a Calendar of the Saints of Ireland, translated from the original Irish by the late John O'Donovan; edited by James Henthorn Todd and William Reeves. (Reviewed).
  Foilsithe / Cruthaithe: (1864)
• Letters from John O'Donovan to George Petrie, William Reeves, and James Henthorne Todd.
• A copy of a letter in the autograph of John O'Donovan, written to Dr. Todd in 1843, giving an account of the author's early life.
  de réir: Reeves, William
  Foilsithe / Cruthaithe: (1884)
• A letter of John O'Donovan to J. H. Todd re St. Lachtin and Ballaghawr, Cork.
  de réir: Macalister, Robert Alexander Stewart
  Foilsithe / Cruthaithe: (1917)
• Letters from John O'Donovan to Rev. J. H. Todd, dealing with old Irish literature and antiquities, 1836 - 1858.