| A calendar of salved chancery pleadings concerning County Louth | Nicholls, K. W. (Kenneth W.) | Article in Journal | | 1975 |
| A charter of John, lord of Ireland, in favour of Matthew Ua Hénni, archbishop of Cashel | Nicholls, K. W. (Kenneth W.) | Article in Journal | | 1983 |
| A charter of William de Burgo | | Article in Journal | | 1972 |
| A landmark publication in traditional Irish genealogy | Nicholls, K. W. (Kenneth W.) | Article in Journal | | 2005 |
| A list of the monasteries in Connacht, 1577 | NA | Article in Journal | | 1972 |
| Abstract of Mandeville deeds | Nicholls, K. W. (Kenneth W.) | Article in Journal | | 1985 |
| Anglo-French Ireland and after | Nicholls, K. W. (Kenneth W.) | Article in Journal | | 1982 |
| Annals of the kingdom of Ireland from the earliest times to the year 1616 | | Monograph or Collective Volume | De Búrca Rare Books | 1990 |
| Celtic contrasts : Ireland & Scotland | Nicholls, K. W. (Kenneth W.) | Article in Journal | | 1999 |
| Crioch Branach : the O'Byrnes and their country | Nicholls, K. W. (Kenneth W.) | Article in Book | | 1998 |
| Further notes on Ormond material in National Library | Nicholls, K. W. (Kenneth W.) | Article in Journal | | 1977 |
| Gaelic and Gaelicized Ireland in the Middle Ages | Nicholls, K. W. (Kenneth W.) | Monograph or Collective Volume | Gill & Macmillan | 1972 |
| Gaelic landownership in Tipperary from the surviving Irish deeds | Nicholls, K. W. (Kenneth W.) | Article in Book | | 1985 |
| Gaelic society and economy in the high middle ages | Nicholls, K. W. (Kenneth W.) | Article in Book | Clarendon Press | 1987 |
| Genealogy | Nicholls, K. W. (Kenneth W.) | Article in Book | | 2000 |
| Genealogy of O'Mahony : translation of a 15th century record | Nicholls, K. W. (Kenneth W.) | Article in Journal | | 1976 |
| Inquisitions of 1224 from the 'Miscellanea of the Exchequer' | | Article in Journal | | 1972 |
| Ireland in 1534 | Nicholls, K. W. (Kenneth W.)Quinn, D. B. (David Beers) | Article in Book | | 1976 |
| Irishwomen and property in the sixteenth century | Nicholls, K. W. (Kenneth W.) | Article in Book | | 1991 |
| Kinelmeaky and the Munster plantation | Nicholls, K. W. (Kenneth W.) | Article in Journal | | 1980 |
| Land, law and society in sixteenth-century Ireland | Nicholls, K. W. (Kenneth W.) | Monograph or Collective Volume | National University of Ireland | 1976 |
| Late medieval Irish annals : two fragments | Nicholls, K. W. (Kenneth W.) | Article in Journal | | 1983 |
| Medieval Irish cathedral chapters | Nicholls, K. W. (Kenneth W.) | Article in Journal | | 1973 |
| Medieval Leinster dynasties and families : three topographical notes | Nicholls, K. W. (Kenneth W.) | Article in Journal | | 1986 |
| Miscellanea : counties Carlow and Wicklow | Nicholls, K. W. (Kenneth W.) | Article in Journal | | 1971 |
| O'Bryne genealogical charts | Nicholls, K. W. (Kenneth W.) | Article in Book | | 1998 |
| Rectory, vicarage, and parish in the western Irish dioceses | Nicholls, K. W. (Kenneth W.) | Article in Journal | | 1971 |
| Review article : Worlds apart? The Ellis two-nation theory on late medieval Ireland | Nicholls, K. W. (Kenneth W.) | Article in Journal | | 1999 |
| Scottish mercenary kindreds in Ireland, 1250-1600 | Nicholls, K. W. (Kenneth W.) | Article in Book | | 2007 |
| Sixteenth- and early seventeenth-century Cork | Nicholls, K. W. (Kenneth W.) | Article in Book | | 2005 |
| Some documents on Irish law and custom in the sixteenth century | Nicholls, K. W. (Kenneth W.) | Article in Journal | | 1970 |
| Some Patrician sites of eastern Connacht | Nicholls, K. W. (Kenneth W.) | Article in Journal | | 1973 |
| Some place-names from 'The Red Book of the Earls of Kildare' | Nicholls, K. W. (Kenneth W.) | Article in Journal | | 1969 |
| Some place-names from Pontificia Hibernica | Nicholls, K. W. (Kenneth W.) | Article in Journal | | 1969 |
| Some unpublished Barry charters | | Article in Journal | | 1972 |
| T.C.D. manuscript : a new source for O'Mahony genealogy | Nicholls, K. W. (Kenneth W.) | Article in Journal | | 1976 |
| The Anglo-Normans and beyond | Nicholls, K. W. (Kenneth W.) | Article in Book | | 2005 |
| The Butlers of Aherlow and Owles | Nicholls, K. W. (Kenneth W.) | Article in Journal | | 1969 |
| The charter of John, lord of Ireland, in favour of the Cistercian abbey of Baltinglass | Nicholls, K. W. (Kenneth W.) | Article in Journal | | 1985 |
| The descendants of Margaret Dartas | Nicholls, K. W. (Kenneth W.) | Article in Journal | | 1972 |
| The descendants of Oliver Fitzgerald of Belagh | Nicholls, K. W. (Kenneth W.) | Article in Journal | | 1968 |
| The development of lordship in county Cork, 1300-1600 | Nicholls, K. W. (Kenneth W.) | Article in Book | | 1993 |
| The early Keatings | Nicholls, K. W. (Kenneth W.) | Article in Journal | | 1976 |
| The episcopal rentals of Clonfert and Kilmacdaugh [c. 1565-7] | | Article in Journal | | 1971 |
| The Fitzmaurices of Kerry | Nicholls, K. W. (Kenneth W.) | Article in Journal | | 1970 |
| The Gaelic Lords in the seventh to sixteenth centuries | Nicholls, K. W. (Kenneth W.) | Article in Book | | 2005 |
| The genealogy of the O'Byrnes of Ranelagh | Nicholls, K. W. (Kenneth W.) | Article in Journal | | 1998 |
| The Geraldines of Allen | Nicholls, K. W. (Kenneth W.) | Article in Journal | | 1968 |
| The Geraldines of Decies | Nicholls, K. W. (Kenneth W.) | Article in Journal | | 1978 |
| The historical writings of Kenneth Nicholls | | Article in Book | | 2004 |
| The Irish fiants of the Tudor sovereigns during the reigns of Henry VIII, Edward VI, Philip and Mary, and Elizabeth I | | Monograph or Collective Volume | Éamonn de Búrca | 1994 |
| The Irish genealogies : their value and defects | Nicholls, K. W. (Kenneth W.) | Article in Journal | | 1974 |
| The Kavanaghs, 1400-1700 | Nicholls, K. W. (Kenneth W.) | Article in Journal | | 1981 |
| The land of the Leinstermen | Nicholls, K. W. (Kenneth W.) | Article in Journal | | 1984 |
| The Lisgoole agreement of 1580 | Nicholls, K. W. (Kenneth W.) | Article in Journal | | 1969 |
| The Mac Carthaigh Mórs in the sixteenth and seventeenth centuries | Nicholls, K. W. (Kenneth W.) | Article in Book | | 2005 |
| The MacCoghlans | Nicholls, K. W. (Kenneth W.) | Article in Journal | | 1983 |
| The name of Mullinahone | Nicholls, K. W. (Kenneth W.) | Article in Journal | | 1977 |
| The O'Byrne Sept of Knockrath | Nicholls, K. W. (Kenneth W.) | Article in Journal | | 1998 |
| The O'Doyne (Ó Duinn) manuscript : documents relating to the family of O'Doyne (Ó Duinn) from Archbishop Marsh's Library, Dublin, MS Z.4.2.19 | | Monograph or Collective Volume | Stationery Office for the Irish Manuscripts Commission | 1983 |
| The other massacre : English killings of Irish, 1641-3 | Nicholls, K. W. (Kenneth W.) | Article in Book | | 2007 |
| The Pipe Roll of Cloyne (Rotulus pipae Clonensis) | | Monograph or Collective Volume | Cloyne Literary and Historical Society | 1996 |
| The protean placename | Nicholls, K. W. (Kenneth W.) | Article in Book | | 2004 |
| The register of Clogher | | Article in Journal | | 1969 |
| The register of Clogher | Nicholls, K. W. (Kenneth W.) | Article in Journal | | 1971 |
| The will of Robert Forstall of Kilferagh, 1645 | | Article in Journal | | 1993 |
| Three topographical notes. I O'Kelly : Uí Chellaig Chualann. II Uí Maíleruba. III MacCon Lothair | Nicholls, K. W. (Kenneth W.) | Article in Journal | | 1986 |
| Tobar Finnmhuighe-Slán Pádraig | Nicholls, K. W. (Kenneth W.) | Article in Journal | | 1967 |
| Towards a new 'Monasticon Hibericum' | Nicholls, K. W. (Kenneth W.) | Article in Journal | | 1984 |
| Tuath-Bailenangeadh (Twoghballynegee, etc.) | Nicholls, K. W. (Kenneth W.) | Article in Journal | | 1967 |
| Visitations of the dioceses of Clonfert, Tuam and Kilmacduagh, c. 1565-7 | | Article in Journal | | 1970 |
| Woodland cover in pre-modern Ireland | Nicholls, K. W. (Kenneth W.) | Article in Book | | 2001 |