Ireland has had nobles or peers for over a millennium. They fall into a number of categories.

1. Ancient Irish Gaelic nobles (pre-English rule)
2. Peers of the Lordship of Ireland and the Kingdom of Ireland (created between 1171 and 1899)
3. Peers of the United Kingdom of Great Britain and Ireland (from 1801)

This list covers peerages possessed by Irish people from any of the three categories. The title is listed first, followed by famous figures associated with the family beneath. It does not include non-Irish people awarded Irish titles; for example, the Duke of Connaught, son of Queen Victoria.

Gaelic Nobles

From 1943 until 2003 some of the modern representatives of the Gaelic nobility obtained official recognition as Chiefs of the Name from the Irish government. During the 1990s this process was subverted, causing the government to abandon the practice and withdraw recognition in 2003. Those chiefs whose recognition was uncontroversial were:

• The O'Conor Don - Descendant of the last High King of Ireland, Rory O'Connor.

Family Seat: Clonalis House.

• The O'Brien (also known as Lord Inchiquin(1543 Kingdom of Ireland barony))

Family Seat: Dromoland Castle (until twentieth century)

• The O'Callaghan
• The O'Donoghue of the Glens
• The O'Donovan
• The MacGillycuddy of the Reeks
• The O'Grady of Kilballyowen
• The O'Kelly of Gallagh and Tycooly
• The MacDermot, Prince of Coolavin
• The O'Neill of Clanaboy
• The O'Dogherty of Inishowen
• The O'Donel of Tirconnell
• The MacMorrough Kavanagh
• The O'Morchoe
• The Fox

To this list may be added modern representatives of the Gaelic nobility who did not apply for recognition. The most notable of these is The O Neill Mór (otherwise known as Carlos O'Neill, Marques de la Granja).

Peerages created by Kings of England/Great Britain/United Kingdom

see also Peerage of Ireland and Anglo-Irish.

• The Duke of Leinster, (formerly known as the Earl of Kildare), Ireland's premier peer.
  • Garret (Mór) FitzGerald - viceroy under King Henry VIII
  • Garret (Óg) FitzGerald - son of the above and also a viceroy
  • Silken Thomas - son of the above, rebelled against Henry VIII and was executed.
  • Lord Edward FitzGerald - 18th century rebel associated with 1798 rebellion

Family seats: Carton House, Co. Kildare (until early 20th century) Leinster House, Dublin City (until beginning of the 19th century - now seat of Dáil Éireann)

• The Duke of Abercorn --title created in 1868 for heir male of the Hamilton family
• The Marquess Conyngham
  • Henry,Lord Mountcharles --son of the 7th Marquess Conyngham, rock impressario and unsuccessful Dáil candidate for Fine Gael in the 1992 Irish general election.

Family Seat: Slane Castle, Co. Meath.

• Baron Killanin
  • Lord Killanin - head of the International Olympic Committee
  • Michael (Mouse) Morris - successful Irish jockey and horse-trainer.

• Earl of Longford
  • 6th Earl of Longford - theatre manager in the Gate Theatre in Dublin.
  • Frank Pakenham, 7th Earl of Longford, (brother of the 6th earl) - British politician, author and campaigner.
  • Lady Antonia Fraser, (daughter of Frank Pakenham) historian and author
  • Thomas Pakenham, 8th Earl of Longford - author

Family Seat: Tullynally Castle (formerly called Pakenham Hall), Co. Westmeath.

• Viscount Powerscourt

Family seats: Powerscourt House, Co. Wicklow (until mid 20th century - house subsequently destroyed by fire); Powerscourt House, Dublin (until 19th century - now a famous shopping arcade)

• Baron Dunsany
  • Edward John Moreton Drax Plunkett, 18th Baron - author and dramatist
  • St. Oliver Plunkett - martyred Roman Catholic Archbishop of Armagh, canonised by Pope Paul VI in 1976

Family Seat: Dunsany Castle, Co. Meath

• The Earl of Fingall
  • Countess of Fingall - author of Seventy Years Young

(title extinct 1984...distant kin to the Lords Dunsany)

Family Seat: Killeen Castle, Co. Meath (until mid 20th century. Castle burned by the Provisional IRA in 1981)

• The Marquess of Londonderry
  • Robert Stewart, Viscount Castlereagh, later 2nd Marquess - politician involved with the passage of the Irish Act of Union 1799-1801.
  • Lord Londonderry - Ulster Unionist Party Minister for Education in Northern Ireland
  • Lady Londonderry - society host, friend of Winston Churchill and Michael Collins, Irish republican leader