The Dukedom of Wellington, derived from Wellington in Somerset, is a hereditary title and the senior Dukedom in the Peerage of the United Kingdom. The first holder of the title was Arthur Wellesley, 1st Duke of Wellington (1769–1852), the noted Anglo-Irish soldier and statesman, and indeed an unqualified reference to the Duke of Wellington in a historical text or to a monument will almost certainly be a reference to this man.

The titles of Duke of Wellington and Marquess Douro were bestowed upon Arthur Wellesley, 1st Marquess of Wellington, on May 11, 1814. The subsidiary titles of the Duke of Wellington are: Marquess of Wellington (1812), Marquess Douro (1814), Earl of Mornington (1760 - but only inherited by the Dukes of Wellington in 1863), Earl of Wellington (1812), Viscount Wellesley (1760 - inherited in 1863), Viscount Wellington (1809), Baron Mornington (1746 - also inherited in 1863) and Baron Douro (1809). The Viscountcy of Wellesley and the Barony and Earldom of Mornington are in the Peerage of Ireland; the rest are in the Peerage of the United Kingdom.

The Dukes of Wellington also hold the foreign titles of Prince of Waterloo (The Netherlands, 1815), Duque de Ciudad Rodrigo (Spain, 1812), Duque de Vittoria and Marques de Torres Vedras (Portugal, 1812) and Conde de Vimeiro (Portugal,1811). These were conferred on the first Duke for his services in the Peninsular War and at the Battle of Waterloo.

Dukes of Wellington (1814)

• Arthur Wellesley, 1st Duke of Wellington (1769-1852)
• Arthur Richard Wellesley, 2nd Duke of Wellington (1807-1884)
• Henry Wellesley, 3rd Duke of Wellington (1846-1900)
• Arthur Charles Wellesley, 4th Duke of Wellington (1849-1934)
• Arthur Charles Wellesley, 5th Duke of Wellington (1876-1941)
• Henry Valerian George Wellesley, 6th Duke of Wellington (1912-1943)
• Gerald Wellesley, 7th Duke of Wellington (1885-1972)
• Arthur Valerian Wellesley, 8th Duke of Wellington (b. 1915)

The current heir to the title is the 8th Duke's son Arthur Charles Valerian Wellesley, Marquess of Douro (b. August 19 1945). (He has chosen to use the style "Marquess of Douro", even though the peerage held by his father is "Marquess Douro".) His son and heir is Arthur Gerald Wellesley, Earl of Mornington (b. January 31 1978).