The O'Toole (Irish: Ó Tuathail) family of Leinster, formerly one of the leading Royal families of that province, are descended from Tuathal Mac Augaire, King of Leinster (died 958), who belonged to the Uí Dúnlainge dynasty.
The first to use the surname in true hereditary fashion appears to have the grandson of Tuathal Mac Augaire, Doncaon, slain at Leighlin in 1014.
Their original territory comprised the southern part of the present County Kildare but they were driven from it during the Anglo Norman invasion and settled in the mountains of what is now County Wicklow around Glendalough through the 12th century. The area they controlled was roughly identical to the old diocese of Glendalough, with the centre of their power in the region around the Glen of Imaal.
Despite the proximity of Dublin, the centre of English rule in Ireland, the Ó Tuathail's maintained a fierce independence, and were a source of great fear to the inhabitants of Dublin and the Pale for almost four centuries. With their kinsmen the O'Byrne family, they were noted for their tough resistance to English domination, including exercising great influence over the foundation of the Confederation of Kilkenny in 1642 in what had become Confederate Ireland.
At the start of the 16th century, there were five great houses, all, owing allegiance to "The O'Toole of Powerscourt" as the recognized chief:
- O'Toole of Castleruddery, residing in Glen Imaile.
- O'Toole of O'Toole's Castle, Ballymacledy, (now Upper Talbotstown), Glen Imaile.
- O'Toole of Carnew Castle.
- Art Oge O'Toole of Castle Kevin, Fertie.
- Tirlogh O'Toole of Powerscourt, Feracualan.
- O'Toole of Omey, Iar Connaught, with other minor houses of the family such as OToole of Ballineddan and Brittas, in the Glen Imaile; O'Toole of Toolestown, near Dunlavin; O'Toole of Glengap, or Glen of the Downs (as it is now called); and a few others.
At the start of the 16th century, the leading branches of the clan were to a certain extent independent of each other; they were all bound to protect themselves; but in external matters affecting the whole clan they were bound to obey the head of the sept.
Throughout their history the family were famous as soldiers, from fighting the English in the glens of Wicklow to serving in the armies of other Catholic European countries in the 18th century, such as France and Spain.
The descendants of the sept took the name O'Toole, although the name is now rare without the prefix 'O'. The tradition of surnames in Ireland developed spontaneously, as the population increased and the former practice, first of single names and then of ephemeral patronymics or agnomina of the nickname type proved insufficiently definitive. At first the surname was formed by prefixing 'Mac' to the father's Christian name or 'Ó 'to that of a grandfather or earlier ancestor.
The following is a list of names that are related to O'Tuathail. This is not a complete list; there may be other names.
- Thomas Kevin O'Toole II is the father of Thomas Kevin O'Toole III and brother to Casey Daniel O'Toole. Husband to Theresa Margaret O'Toole. He is a businessman and entrepreneur.
- Saint Laurence O'Toole was an archbishop of Glendalough and in 1171, while he was Archbishop of Dublin he took up arms against the Anglo Norman invaders.' He was canonized in 1225 by Pope Honorius III.
- Mór Ní Tuathail (c. 1114–1191) was a Queen-consort of Leinster as the first wife of King Diarmait Mac Murchada. Mór was the mother of Aoife of Leinster, the wife of Richard de Clare, Earl of Pembroke, known to history as Strongbow.
- Colonel John O'Toole of the Irish Brigade in France was created a count and is the ancestor of the present Count O'Toole of Limoges.
- Sergeant O'Toole of the 9th Queen's Royal Lancers of the British Army was awarded a Victoria Cross for conspicuous bravery in the Zulu War on 3 July 1879.
- John Lawrence Toole (1830–1906) the comedian, born in London. He went to the City of London School, and in 1853 gave up his desk in a wine merchants to become an actor. He first played at Ipswich and in London at the St. James's Theatre in 1854. In 1874-75 he played in the United States, and in 1890 in Australia. In 1879 he became lessee of the Folly Theatre, which he enlarged, changing the name to 'Toole's Theatre'.
- Peter O'Toole (1932-2013) was a noted English stage and screen actor. He received three Golden Globes, an Emmy Award and eight Oscar nominations. He was awarded an honorary Oscar for his body of work in 2003. He starred in such films as Lawrence of Arabia, The Lion in Winter, and Goodbye, Mr. Chips.
- John Albert O'Toole was assigned to USS Joseph Hewes (AP-50) and commanded a boat wave from that transport during the assault on Fedhala, Morocco, 8 November 1942. He was posthumously awarded the Navy Cross and the USS O'Toole (DE-527)Evarts-class destroyer escort was named in his honor.
- Gerard Toal (Irish: Gearóid Ó Tuathail) (born 1962) is a Professor of Government and International Affairs in Washington DC
- Fintan O'Toole is an Irish journalist, author and critic, best known for his work with The Irish Times.
- Rich O’Toole is an award winning singer - songwriter from Houston,TX
- Gary O'Toole is a former World champion and represented Ireland twice in the Olympics, 1988 and 1992. Now a leading Orthopaedic Consultant in Ireland.
- Mark O'Toole is the former bassist and a founding member of 1980s pop band, Frankie Goes to Hollywood.
- Kevin F. O’Toole is the Executive Director of the Pennsylvania Gaming Commission.
- Hm3 Skylar J. O’Toole is a former United States Navy Hospital Corpsman who fought in the Battle of Sangin (2010), and later Marjah with 2nd Battalion, 9th Marines during the War in Afghanistan.
- O'Toole, Patrick Laurance (1890). History of the Clan O'Tool and other Leinster Septs. Dublin: M. H. Gill and son; New York, Benziger brothers; [etc., etc.]
This article incorporates text from a publication now in the public domain: "History of the Clan O'Tool and other Leinster Septs" by Patrick Laurance O'Toole