Contains a copy of a single letter from J.J. O'Kelly to "The Competent Military Authority of Dublin Castle" concerning various papers seized by the Castle follow O'Kelly's arrest. O'Kelly requests their return.

While the letter has O'Kelly's address in Glasnevin the date corresponds to his imprisonment in Arbour Hill in 1921,

Contains a single letter from J.J. O'Kelly to Art O'Connor during O'Connor's time as titular president of the Republic following De Valera's resignation.

Contains a single typescript letter from J.J. O'Kelly to Frederick A. Sterling, U.S. Minister to Ireland, concerning the legality and morality of the American decision to recognize of the Free State and a partitioned Ireland.

Contains two typescript letters, one to Éamon de Valera and one to An Phoblacht concerning De Valera's misappropriation of funds from Dáil Éireann.

Contains four letters from J.J. O'Kelly to various recipients, including a Dáithí Ó Conchubhair and a Reverend Sheen.

Contains nine letters from J.J. O'Kelly to various recipients, including a "Mrs. Brugha," almost certainly Caitlín Brugha, former Teachta Dala for Waterford and widow of Cathal Brugha.

Contains eighteen letters from J.J. O'Kelly to various recipients.

Contains nine drafts of letters from J.J. O'Kelly to various recipients.

Contains five letters in correspondence between J.J. O'Kelly and Maurice R. O'Connell. Included with two of Maurice's letters are a typed copy of the inscription of the tomb of Donal Mór, Máire-ní-Duiv and Hunting-Cap, and a typed copy of a number of Daniel O'Connell's letters to his son, Maurice O'Connell.

Contains three letters in correspondence between J.J. O'Kelly and a Mr. H. Cerowski concerning O'Kelly's book O'Connell Calling and Cerwoski's desire to write a book about Poland in 1846-1848 from an Irish perspective.

Contains one letter from Norma Bhortuic [Borthwick], Irish language activist, writer, and artist, to J.J. O'Kelly.

Contains one letter from Earnan de Siúnta, engineer and Irish language enthusiast, to J.J. O'Kelly.

Contains one letter from Seamus Ó Conchubhair to J.J. O'Kelly.

Contains a form letter from the Governor of Reading Prison to J.J. O'Kelly.

Contains a letter from solictor and Irish Republican Brotherhood member Seoirse MacNiocaill to J.J. O'Kelly. Pertains to MacNiocaill's return from Frongoch Interment Camp, though in vague detail.

Contains a letter from Máire Nic Shuibhne, deputy leader of Sinn Féin, to J.J. O'Kelly.

Contains two letters from Seán Mac Craith of Westport, Co. Mayo, to J.J. O'Kelly.

Contains four letters from Tadhg Ó Donnchadha 'Torna,' Professor of Irish at University College Cork, to J.J. O'Kelly.

Contains one typescript letter from Aindrias Ó Muimhneacháin, Irish teacher and member of Conradh na Gaeilge's Coiste Gnótha, to J.J. O'Kelly. Additionally included as part of Ó Muimhneacháin's letter is a letter from a Pádraig Uí Éigeartaigh of Springfield, Massachusetts, to Ó Muimhneacháin.

Contains two letters, one typescript and one manuscript, from Proinsias E. Ó Súilleabháin, an inspector of elementary schools and Irish language advocate, to J.J. O'Kelly. One letter is marked 'strictly confidential' in green ink and an unknown hand.

Contains one letter from Irish writer Tadhg S. Seoighe to J.J. O'Kelly, concerning Seoighe's book, Scealta Cois Teallaigh.

Contains one letter from a WOB, surname illegibile, located at Clounclohessy near Shanagolden, Limerick to J.J. OKelly. Letter congratulates O'Kelly on his return from Germany and generally praises Hitler.

Contains one brief letter from Eduard Hempel, a German diplomat in Ireland, to J.J. O'Kelly concerning O'Kelly's pamphlet "Stepping Stones."

Contains one letter from Irish translator and Russian lecturer, Maighréad Nic Mhaicín to J.J. O'Kelly

Contains one letter from writer Mary Purcell to J.J. O'Kelly concerning the writing of her book on St. Francis Xavier, later published as Don Francisco; The story of St. Francis Xavier.

Contains two letters of personal correspondence to J.J. O'Kelly from various senders. The January 1917, from the Friary in Kilkenny, is primarily concerned with Constance Markiewicz and the false rumors which were circulated about her.

Contains seven letters of personal correspondence to J.J. O'Kelly from various senders. Includes one poem by a Fionan O'Shea.

Contains thirty-four letters of personal correspondence to J.J. O'Kelly from various senders.

Contains twenty-four letters of personal correspondence to J.J. O'Kelly from various senders. Includes letters from a B. Baker, a catholic chaplain in the Simla Hills, India, Count Plunkett, and the "Most Honourable Dalcassian Order of the Princely House of Thomond." A pamphlet detailing the life of Father James Anderson, OSA, accompanies a letter written by a Francis Xavier Martin, OSA, as well.

Contains ten letters, one telegram, and an invitation to J.J. O'Kelly from various senders. One letter, dated 13 June 1967, was either sent after O'Kelly's death in 1957 or erroneously dated.