The title of Marquess of Abergavenny (pronounced "Abergenny") was created in 1876 in the Peerage of the United Kingdom for the Earl of Abergavenny.

The Marquess holds the subsidiary titles of Earl of Abergavenny (Great Britain, 1784), Earl of Lewes (U.K., 1876) and Viscount Nevill (Great Britain, 1784).

One of the best known of English noble families, the Nevilles, acquired the title and estates of the Barony of Abergavenny when the honour was bestowed upon Edward Nevill, who was summoned to parliament under this title in 1450. Edward Nevill was the youngest son of the 1st Earl of Westmoreland, by Joan Beaufort, the daughter of John of Gaunt. Nevill married the heiress of Richard Beauchamp, Earl of Worcester, whose father had inherited the castle and estate of Abergavenny, and was summoned to parliament in 1392 as the Lord Bergavenny. The Barony of Bergavenny fell into abeyance on the death of the 5th Marquess in 2000.

Earls of Abergavenny (1784)

• George Nevill, 1st Earl of Abergavenny (1727_1785)
• Henry Nevill, 2nd Earl of Abergavenny (1755_1843)
• John Nevill, 3rd Earl of Abergavenny (1789_1845)
• William Nevill, 4th Earl of Abergavenny (1792_1868)
• William Nevill, 5th Earl of Abergavenny (1826_1915) (became Marquess of Abergavenny in 1876)

Marquesses of Abergavenny (1876)

• William Nevill, 1st Marquess of Abergavenny (1826_1915)
• Reginald William Bransby Nevill, 2nd Marquess of Abergavenny (1853-1927)
• Henry Gilbert Ralph Nevill, 3rd Marquess of Abergavenny (1854-1938)
• Guy Temple Montacute Larnach-Nevill, 4th Marquess of Abergavenny (1883-1954)
• John Henry Guy Nevill, 5th Marquess of Abergavenny (1914_2000)
• Christopher George Charles Nevill, 6th Marquess of Abergavenny (b. 1955)

There is no heir to the Marquessatate of Abergavenny and the Earldom of Lewes.

Heir Presumptive to the Earldom of Abergavenny and Viscountcy of Nevill: John Robert Ralph Nevill (great-great-great-grandson of the 1st Earl of Abergavenny)