Dudley House is a Grade II* listed house with 44,000 square feet (4,100 m2) located at 100 Park Lane in Mayfair, London. It is one of the few surviving aristocratic townhouses in London. Dudley House is named after the Ward family, holders of the titles of Baron Ward, Viscount Dudley and Ward, and Earl of Dudley.
An earlier house with stabling on the site was acquired in 1742 by the 6th Baron Ward. In 1759, the 3rd Viscount Dudley and Ward undertook substantial alterations to the property. Between 1827 and 1829, the 1st Earl of Dudley, of the first creation, rebuilt the house to the plans of the architect William Atkinson. The Earl died childless and insane in 1833, and the house was leased to the 2nd Marquess Conyngham and then to the 2nd Marquess of Abercorn.
In 1847, the Earl's cousin, the 11th Lord Ward, took over the house and remained there until his death in 1885, by which time he had become the 1st Earl of Dudley, of the second creation. In 1855, he commissioned alterations from architect Samuel Whitfield Daukes that were most impressive, including an 81 ft picture gallery and a 50 ft ballroom. After inheriting from his father, the 2nd Earl of Dudley extended the conservatory over the porch.
In 1895, the house was sold to Sir Joseph Robinson, 1st Baronet, a South African mining magnate. Robinson frequently used the house for entertaining, hosting performances by singers Nellie Melba and Clara Butt at the house. In 1912, Sir John Hubert Ward bought the building back for 10,000 pounds, and remained there until his death in 1938.
Dudley House was severely damaged in the Blitz in World War II, and the property reverted into the possession of the Grosvenor Estate. It became a temporary office, before it began to deteriorate into a near ruin. Hammerson, a British property development and investment company, converted the house into offices, to designs by architects Sir Basil Spence and Anthony Blee in 1969-70. The architects remained sympathetic to Dudley House's historic interiors, but the rear of the house was completely reconstructed, the war-damaged ballroom and picture gallery disappearing, with only sections of the ceiling of the latter surviving under a false-ceiling. The house remained as offices for sixty years before its reversion to a private residence.