| Marquessate of Sligo | |
|---|---|
  Arms: Sable, three Lions passant in bend Argent, between four Bendlets Argent. Crest: An Eagle displayed Vert. Supporters: Dexter: A Talbot gorged with a Baron’s Coronet proper; Sinister: A Horse Argent. | |
| Creation date | 29 December 1800 |
| Created by | George III |
| Peerage | Peerage of Ireland |
| First holder | John Browne, 3rd Earl of Altamont |
| Present holder | Sebastian Browne, 12th Marquess of Sligo |
| Heir apparent | Christopher Browne, Earl of Altamont and Clanricarde |
| Remainder to | Heirs male of the first Marquess's body lawfully begotten |
| Subsidiary titles | Earl of Altamont Earl of Clanricarde Viscount Westport Baron Mount Eagle Baron Monteagle |
| Status | Extant |
| Former seat(s) | Westport House |
| Motto | SUIVEZ RAISON ("Follow the right") |
Marquess of Sligo is a title in the Peerage of Ireland. It was created in 1800 for John Browne, 3rd Earl of Altamont. The Marquess holds the subsidiary titles of Baron Mount Eagle, of Westport in the County of Mayo (created 10 September 1760), Viscount Westport, of Westport in the County of Mayo (created 24 August 1768), Earl of Altamont, in the County of Mayo (created 4 December 1771), Earl of Clanricarde (created 1800) and Baron Monteagle, of Westport in the County of Mayo (created 20 February 1806). All these titles are in the Peerage of Ireland, except the Barony of Monteagle, which is in the Peerage of the United Kingdom. The latter peerage entitled the Marquesses to a seat in the House of Lords prior to the House of Lords Act 1999. The Earldom of Clanricarde was inherited by the sixth Marquess in 1916 according to a special remainder in the letters patent.