Clarence House is a British royal residence on The Mall in the City of Westminster, London. It is attached to St James's Palace and shares the palace's garden. From 1953 until 2002, it was home to Queen Elizabeth The Queen Mother. It has since been the official residence of Charles, Prince of Wales, and his wife Camilla, Duchess of Cornwall.
Clarence House was also the official residence of Prince William from 2003 until April 2011, and of Prince Harry from 2003 until March 2012. It is open to visitors for approximately one month each summer, usually in August. The four-story house is faced in pale stucco.
Over the years, it has undergone extensive remodelling and reconstruction, most notably after the Second World War, and little remains of the original structure as designed by John Nash. Since 2003, the term Clarence House has been used as a metonym for the Prince of Wales's private office. (The term St James's Palace had been used previously.) It is Grade I listed on the National Heritage List for England.
The house was built between 1825 and 1827 to a design by John Nash. It was commissioned by the Duke of Clarence, who in 1830 became King William IV of the United Kingdom (reigned 1830-1837). He lived there in preference to the adjacent St James's Palace, an ancient Tudor building which he found too cramped.
From William IV, the house passed to his sister Princess Augusta Sophia, and, following her death in 1840, to Queen Victoria's mother, Princess Victoria of Saxe-Coburg-Saalfeld.  In 1866, it became the home of Queen Victoria's second son Alfred, Duke of Saxe-Coburg and Gotha (also Duke of Edinburgh), until his death in 1900.
Alfred's younger brother Prince Arthur, Duke of Connaught and Strathearn, Queen Victoria's third son, used the house from 1900 until his death in 1942. During his tenure, for a brief period in the 1930s, it was the location of the library of the School of Oriental and African Studies until all universities in London were evacuated in 1939, and the school temporarily relocated to Cambridge.
During World War II, it suffered damage by enemy bombing during The Blitz (1940-41). Following the death of the Duke of Connaught in 1942, it was used by the Red Cross and the St John Ambulance Brigade as their headquarters during the rest of World War II.
In 1953, after the death of her father King George VI (d. 6 February 1952), and her accession as Queen Elizabeth II, she moved to Buckingham Palace. Her mother, Queen Elizabeth, and Princess Margaret moved into Clarence House. Also at the start of her widowhood, the Queen Mother purchased the Castle of Mey in Scotland as a summer residence.
Princess Margaret later moved into an apartment in Kensington Palace, whilst the Queen Mother remained at Clarence House and at the Castle of Mey, until her death in March 2002. In 2003, the Prince of Wales moved to Clarence House.