Apsley House , also known as Number 1, London , was the London residence of the First Duke of Wellington and stands alone at Hyde Park Corner, on the south-east corner of Hyde Park, facing south towards the busy traffic circulation system.

It was originally built in red brick by Robert Adam between 1771 and 1778 for lord high chancellor Baron Apsley who later became the 2nd Earl Bathurst, and who and gave the house its name.

The house was given the popular nickname of Number 1, London, since it was the first stately house encountered by visitors who travelled from the countryside after the toll gates at Knightsbridge. It was originally part of a line of great houses continuous with Piccadilly. Its official address is 149 Piccadilly, W1J 7NT.

In 1807 the house was purchased by Marquess Wellesley, the elder brother of Arthur Wellesley, but in 1817 financial difficulties forced him to sell it to his famous brother , then the Duke of Wellington , who needed a London base from which to pursue his new career in politics.

Wellington employed the architect Benjamin Dean Wyatt to carry out renovations between 1818 and 1819. He extended the house by adding two bays to the original five; built the Waterloo Gallery for the Duke's paintings, and faced the red brick with the more fashionable Bath stone. He also introduced his own version of French style to the interior and installed the nude statue of Napoleon by the Italian Neo-classical sculptor Antonio Canova in the stairwell.

The house is now owned by English Heritage and is open as a museum and art gallery. It contains the First Duke's collection of paintings, porcelain, silver, sculpture and furniture. Paintings by artists including Goya, Velasquez, Rubens and Brueghel. The current Duke of Wellington has a residence on the second floor (third floor in American English).