Wellington Arch, also known as Constitution Arch, is a triumphal arch located to the south of Hyde Park in central London. It was built in 1828 to a design by Decimus Burton as a memorial to Sir Arthur Wellesley, 1st Duke of Wellington, soldier and Prime Minister.

The arch originally stood next to Apsley House as a grand western entrance to London and was crowned with a giant statue of the Duke, by Matthew Cotes Wyatt . In 1883, the arch was moved to its present location on Hyde Park Corner to facilitate a road widening scheme. It is today in the centre of a large traffic island.

The statue was removed to Aldershot at the same time and was eventually replaced, in 1912, by a huge bronze quadriga designed by Adrian Jones . The sculpture shows a small boy (actually the son of Lord Michelham , the man who funded the sculpture) leading the quadriga, with Peace descending upon it from heaven.

The arch is hollow inside, and until 1992 housed the second smallest police station in London (the smallest being in Trafalgar Square). Transferred to the ownership of English Heritage in 1999, it is now open to the public and contains three floors of exhibits detailing the history of the arch and some of its uses.