The numbering starts with Number 1 to the north of Charles Street (now
Charles II Street) on the eastern side of the square and proceeds anti-clockwise as far as Number 21. The
Army and Navy Club's clubhouse occupies the former sites of Number 22, a smaller adjacent house which may have had a George Street number, and several former houses in Pall Mall. Norfolk House at the southern end of the square is Number 31, and the two houses to its north are Numbers 32 and 33. A small house in the angle of the square south of Norfolk House, originally numbered in John Street, and the adjacent house in Pall Mall, have been combined and allocated the number 31A. The smaller houses along the southern side had Pall Mall numbers until 1884. This block is now occupied by a mixture of 19th and 20th century buildings which are fully built up to the pavements on both sides. Some of them have their main entrance in Pall Mall and others in the square, and there are two separate sets of numbers for them. The numbers in the square range from 22A to 30, with some omissions. • No. 1:
BP head office. Also occupies the site of the former No. 2 and several demolished houses in Charles II Street. It is a
post-modern building dating from c.2000 which differs from the Georgian style of the street. It was built to be
Ericsson's London office and was sold to BP for
£117 million in 2001. • No. 3: The original house had many owners and tenants, including the holders of at least three separate dukedoms, and was worked on by various architects including John Soane. General
Augustus Pitt-Rivers lived in the house as a child during the 1830s and 1840s. The present building is a 1930s office block. • No. 4: The
Naval and Military Club in a Georgian house of 1726–28 by
Edward Shepherd. It was the London residence of the
Earls Cowper for much of the 19th Century and its châtelaines included
Emily, Countess Cowper and Viscountess Palmerston and
Ettie Grenfell, Baroness Desborough, niece of the last Earl Cowper. It was also the former home of
Nancy Astor and the only house in the square to retain its large garden and the original mews house to the rear. • No. 5: Wentworth House,
5, St James's Square, built in 1748-51 by
William Wentworth, 2nd Earl of Strafford, to the design of
Matthew Brettingham The Elder 1748–9. Refronted in stone, porch added, and attic converted into a full storey in 1854. Now offices; in 1984 it was the Libyan "People's Bureau", when during the
Libyan Embassy Siege gunshots fired from the building caused the
murder of Yvonne Fletcher. • No. 6: (Under Demolition)
Rio Tinto Group head office. Modern. This building was the home of the Hervey family (Earls and Marquesses of Bristol) for nearly 300 years.
Lord Arthur Hervey was born at the house in 1808. In the 1950s the old building was knocked down, and the family did not return. • No. 7: Neo Georgian, architect
Edwin Lutyens, 1911. • No. 8: Neo Georgian, architects Robert Angell and Curtis, 1939. In November 2007, No. 8 and neighbouring No. 7 were bought for £125m. • Nos. 9 to 11: Numbers 9, 10 and 11 were built in the 1730s on the site of the former Ormonde House, once the largest house in the square.
Henry Flitcroft supervised number 10 and probably also numbers 9 and 11. No. 10 is
Chatham House, former home of British Prime Minister
William Pitt the Elder and of the
Earl and
Countess of
Blessington. There is a
London County Council plaque on Number 10 stating "Here lived Three Prime Ministers WILLIAM PITT Earl of Chatham 1708–1778 Edward Geoffrey Stanley EARL OF DERBY 1799–1869 William Ewart GLADSTONE 1809–1898". • No. 12: Built 1836, probably by
Thomas Cubitt. Former home of
Ada Lovelace. • No. 13: Built 1735–1737, possibly by
Matthew Brettingham. Now houses the
High Commission of the
Republic of Cyprus. • No. 14: Occupied by the
London Library since 1845, rebuilt for them 1896–98 and subsequently extended to the rear. • No. 15: , by
James Stuart, 1764–6. Balcony added circa 1791 by
Samuel Wyatt. So-called after
Thomas Anson, 1st Earl of Lichfield, resident when the
Lichfield House Compact was agreed there in 1835. Now offices. • No. 16 and site of former No. 17:
East India Club, built in 1865 to designs by
Charles Lee. • No. 18: Italianate reconstruction of 1846. Now apartments. • No. 19: The London home of the
Dukes of Cleveland and family from 1720 to 1894. A replacement building of 1898–99 used variously as offices and residentially was replaced by the present stone-clad offices in 1999–2000. Current site of the
Rolex UK headquarters. • No. 20/21:
Robert Adam's reconstruction of No. 20 for Sir
Watkin Williams-Wynn from 1771 to 1775 is one of the most praised of his smaller works. The house was three bays wide and had three main storeys plus an attic. In 1936 it was extended to include the rebuilt No. 21 to its south, forming a uniform seven bay façade with an extra full storey on top. This address became the London offices for the enterprise software company
Autonomy Corporation in December 2010. • (Former) No. 22 and adjacent buildings: replaced by the
Army and Navy Club 1848–51. It had a bold Venetian exterior. This has been lost and the present building is in a mean mid 20th century style. • Nos. 22A to 30: See above. Little historical or architectural significance, except that the now defunct
Junior Carlton Club once occupied a grand clubhouse at the western end of the block. • No. 31:
Norfolk House – the London residence of the
Dukes of Norfolk for many generations, was built between 1748 and 1752 by
Edward Howard, 9th Duke of Norfolk to the design of
Matthew Brettingham "the Elder", and was demolished in 1938. It was then replaced by a neo-Georgian office building of the same name which was U.S. General
Dwight D. Eisenhower's headquarters during the
Second World War, where
Operation Torch and
Operation Overlord were planned. • No. 32: Built by
Samuel Pepys Cockerell and
Charles Robert Cockerell in 1819–21 under the ''''
(59 Geo. 3. c. 45'') as a residence for the
Bishop of London, named London House. In 1851 it was one of the residences of the then Bishop of London,
Charles James Blomfield. Later alterations. Used as offices. • No. 33: By Robert Adam (1770–72) replacing an earlier house. Altered by
John Soane 1817–23. Later alterations including an additional storey, but still essentially Georgian. Used as offices. ==Gardens==