Ní Shéaghdha, Nessa (1916–93), Irish language scholar, was born 14 March 1916 in Drumcondra, Dublin, one of four daughters and a son of Seán Pádraig Ó Séaghdha and his wife, Kitty Nic Caochlaoich. She attended Scoil Bhríde national school and Scoil Chaitríona secondary school and entered UCD in 1936 where she studied old Irish under scholars Osborn Bergin (qv) and Gerard Murphy (qv). Subsequently she completed a master's degree under Bergin's supervision.
On the establishment of the Leabhair ó láimhsgrígbhnigh project in 1937, she was employed as a junior editor to work under Gerard Murphy on editions of Bruidhean chéise coruinn and Bruidhean bheag na hAlmhan for the series Trí bruidhne (1941). The project's primary aim was to publish lengthy texts in Irish never published before. She co-edited a third volume, Bruidhean chaorthainn with Máire Ní Mhuiríosa (qv). The texts were based on manuscripts in the National Library of Scotland, where she spent time researching. During her time there she met the Scottish Gaelic poet Somhairle Mac Gill-Eain, who fell in love with her. She provided inspiration for a number of his poems, published under the title Dáin do Eimhir (1943). On her return to Ireland she met her future husband David Doran, whom she married in 1939; they had three daughters and a son.
Ní Shéaghdha continued her editorial work and by the end of 1945 when the Leabhair ó láimhsgrígbhnigh project ended, she had edited a further four volumes: Stair fhír-cheart ar Éirinn (1941) and Agallamh na seanórach (1942–5) in three volumes. The DIAS School of Celtic Studies was established in 1940 and it was intended that the staff of the Leabhair project would transfer there. Unfortunately for Ní Shéaghdha, only one person, J. P. Carney (qv), was successful in making the transition. The school offered her a commission in 1943 to produce a definitive edition of ‘Tóraigheacht Dhiarmada agus Ghráinne’, eventually published by the Irish Texts Society under the title Tóruigheacht Dhiarmada agus Ghráinne (1967). She was also approached by publishers Browne and Nolan to produce a schools’ edition of the text which appeared in 1944. This text proved to be a bone of contention between Ní Shéaghdha and the then director of the school, T. F. O'Rahilly (qv). Her other publications include Translations and adaptions into Irish (1984); ‘Collectors of Irish manuscripts: motives and methods’ in Celtica xvii (1985) and ‘Irish scholars and scribes in eighteenth-century Dublin’ in Eighteenth-Century Ireland, iv (1989), 41–54.
Ní Shéaghdha was employed as a scholar by the School of Celtic Studies (1950–54) and afterwards as a research assistant until her retirement in 1981. Her main task was the compilation of a catalogue of Irish manuscripts in the NLI. She was author of a total of 11 fasciculi, consisting of approximately 600 Irish language manuscripts, and continued working on the project after her retirement and despite ill health. During the course of her cataloguing work she discovered many valuable manuscripts, including a unique collection of old Irish verse contained in NLI MS G 50. She provided an account of this manuscript in Fasciculus 2 (1961). The manuscript also included the eighth-century poetry of Blathmac (qv), later published by Carney under the title The poems of Blathmac son of Cú Brettan (1964).
She had a charismatic personality and was willing to share her knowledge with others. As well as lecturing in the university colleges, she also acted as external examiner.
Ní Shéaghdha died 11 April 1993 and is buried in Enniskerry cemetery in Co. Wicklow.
More information on this entry is available at the National Database of Irish-language biographies (Ainm.ie).