The following people were educated at Westminster School, and are sometimes listed with OW (Old Westminster) after their name (collectively, OWW) There are over a thousand Old Westminsters listed in the Oxford Dictionary of National Biography so these are necessarily a small sample:

All persons are British unless otherwise stated.

15th century

• John Hygdon (c. 1472 ? 1532), first dean of Cardinal College /Christ Church, Oxford

16th century

• Nicholas Udall (1504?1556), playwright
• Richard Hakluyt (c. 1552 ? 1616), travel writer
• William Alabaster (1567?1640), poet
• Robert Bruce Cotton (1570?1631), antiquarian
• Ben Jonson (1573?1637), poet and dramatist
• Arthur Dee (1579?1651), physician
• Richard Corbet (1582?1635), poet
• Robert Herrick (1591?1674), poet
• Charles Chauncy (1592?1672), President of Harvard 1654 – 72
• Henry King (1592?1669), poet
• George Herbert (1593?1633), public orator and poet

17th century

• Jasper Mayne (1604?1672), dramatist
• Thomas Randolph (1605?1635), poet and dramatist
• Abraham Cowley (1618?1667), poet
• Richard Lower (1631?1691), pioneering physician
• John Dryden (1631?1700), poet and playwright
• John Locke (1632?1704), philosopher
• Sir Christopher Wren (1632?1723), architect, scientist and co-founder of the Royal Society
• Robert Hooke (1635?1703), scientist and co-founder of the Royal Society
• Thomas Gale (c. 1636 ? 1702), classical scholar and antiquarian
• Henry Aldrich 1647 – 1710), philosopher
• George Jeffreys, 1st Baron Jeffreys of Wem (1648?1689), Lord Chief Justice of the Bloody Assize, Lord Chancellor (also ed. by Thomas Chaloner at Shrewsbury and attended St Paul's)^[1]
• Humphrey Prideaux (1648?1724), Dean of Norwich
• Lancelot Blackburne (1658?1743), Archbishop of York
• Henry Purcell (1659?1695), composer
• Charles Montagu, 1st Earl of Halifax (1661?1715), creator of the Bank of England
• James Hamilton, 6th Earl of Abercorn (1661?1734), Privy Counsellor
• William King (1663?1712), poet
• Matthew Prior (1664?1771), poet
• Nicholas Rowe (1674?1718), Poet Laureate 1715
• William Pulteney, 1st Earl of Bath (1684?1764), Cabinet Minister
• John Carteret, 2nd Earl Granville (1690?1763), statesman and Cabinet Minister
• Thomas Pelham-Holles, 1st Duke of Newcastle-upon-Tyne (1693?1768), First Lord of the Treasury 1754 – 1756, Prime Minister
• James Bramston (1694?1744), satirist
• Henry Pelham (1696?1754), First Lord of the Treasury and Chancellor of the Exchequer 1743 – 1754, Prime Minister
• John, Lord Hervey,(1696?1743), statesman and writer
• John Dyer (1699?1748), poet

18th century

• Charles Wesley (1707?1788), Methodist preacher and writer of over 6,000 hymns
• William Beckford (1709?1770), politician, twice Lord Mayor of London
• John Cleland (1709?1789), author of the first erotic novel
• Sir John Eardley Wilmot (1709-1792), Chief Justice of the Common Pleas
• Robert Hay Drummond (1711-1776), Archbishop of York
• James Waldegrave, 2nd Earl Waldegrave (1715?1763), First Lord of the Treasury, Prime Minister for five days in 1757
• Francis Lewis (1713?1803), signatory of the United States Declaration of Independence
• General Thomas Gage (1721?1787), C in C North America, Governor of Massachusetts 1774
• John Burgoyne (1723?1792), Lieutenant-General who surrendered British Army at Saratoga
• Richard Howe, 1st Earl Howe (1726?1799), Admiral of the Fleet
• Frederick Hamilton (1728?1811), deacon
• Charles Watson-Wentworth, 2nd Marquess of Rockingham (1730?1782), Prime Minister
• William Cowper (1731?1800), poet and hymnodist
• Henry Constantine Jennings (1731?1819), collector and gambler
• Charles Churchill, George Colman the Elder, Bonnell Thornton and Robert Lloyd (1731?1764, 1732?1794, 1725?1768, and 1733?1764), satirists and poets; founders of the satirists' Nonsense Club
• Warren Hastings (1732?1818), impeached Governor-General of Bengal
• Nevil Maskelyne (1732?1811), Astronomer Royal
• Richard Cumberland (1732?1811), dramatist
• Augustus Henry Fitzroy, 3rd Duke of Grafton (1735?1811), Prime Minister
• Charles Lennox, 3rd Duke of Richmond (1735?1806), reforming politician
• John Horne Tooke (1736?1812), politician and philologist
• Edward Gibbon, FRS (1737?1794), historian
• William Cavendish-Bentinck, 3rd Duke of Portland (1738?1809), Prime Minister
• Arthur Middleton (1742?1787), signatory of the United States Declaration of Independence
• Charles Cotesworth Pinckney (1746?1825), ADC to Washington 1777, defeated by Jefferson in 1804 in contest for Presidency
• Jeremy Bentham (1748?1832), philosopher, lawyer and eccentric
• Archibald James Edward Stewart, 1st Baron Douglas of Douglas (1748?1827), Winner of the Douglas Cause. MP and Lord Lieutenant of Forfarshire. http://www.jamesboswell.info/People/people.php?id=33
• Henry William Bunbury (1750?1811), caricaturist
• Thomas Pinckney (1750?1828), American ambassador to Britain
• Richard Burke Jr. (1758-1794), Member of Parliament
• Richard Bingham, Earl of Lucan (1764?1839), Member of Parliament
• Thomas Bruce, 7th Earl of Elgin (1766?1841), ambassador to Constantinople, bringer of parthenon marbles to Britain
• Henry William Paget, 1st Marquess of Anglesey (1768?1854), cavalry and horse artillery officer at Waterloo, where he lost a leg
• Sir Francis Burdett, 5th Baronet (1770?1844), Radical parliamentarian and parliamentary reformer
• Robert Southey (1774?1843), Poet Laureate 1813
• Matthew Gregory Lewis (1775?1818), dramatist
• Benjamin Hall (1778?1817), Welsh industrialist, father of 1st Baron Llanover (below).
• Henry Fynes Clinton (1781?1852), scholar
• John Hobhouse, 1st Baron Broughton (1786?1869), companion and ally of Byron
• FitzRoy Somerset, 1st Baron Raglan (1788?1855), lost his right arm at Waterloo, C-in-C in the Crimea
• William Sellon (died 1790), Deacon
• Sir James Graham (1792?1861), politician
• John Russell, 1st Earl Russell (1792?1878), Prime Minister
• William Mure (1799?1860), scholar and politician

19th century

• John Nelson Darby (1800?1882), Irish clergyman
• Thomas Henry Lister (1800?1842), novelist and first Registrar General
• Benjamin Hall, 1st Baron Llanover (1802?1867), Commissioner of Works and Public Buildings responsible for, amongst others, the current Palace of Westminster, likely to have given his name to Big Ben
• Zerah Colburn (1804?1840), Canadian child mathematics prodigy
• William Rowan Hamilton (1805?1865), scientist
• Sir Robert Joseph Phillimore (1810?1885), Judge of the Arches
• Gilbert Abbott à Beckett (1811?1856), writer
• Sir Charles Dilke, 1st Baronet (1811?1869) reformer, instigator of the Great Exhibition
• Henry Mayhew (1812?1887), reforming and satirical journalist ; chronicler of London's poor and founder of Punch
• Sir George Webbe Dasent (1817?1896), author
• George Henty (1832?1902), author of more than 80 popular books for boys
• Sir Edward Poynter (1836?1919), painter
• Sir Charles Dilke, 2nd Baronet (1843?1911), Liberal statesman
• William Knox D'Arcy (1849?1917), industrialist
• Herbert Rawson (1852 - 1924), England international footballer
• Norman Bailey (1857 - 1923), England international footballer
• Sir Guy Francis Laking (1875?1919), art historian and Keeper of the London Museum
• Sir K. A. C. Creswell (1879?1974), architectural historian specialising in Egyptian Islamic architecture
• A. A. Milne (1882?1956), author and journalist
• Hussein Ala (born 1883), Prime Minister of Iran
• Adrian Stephen (1883?1948), Bloomsbury psychoanalyst
• Henry Tizard (1885?1959), scientist and inventor
• Harry St. John Philby (1885-1960), Arabist, explorer, author, agent
• Gustav Hamel (1889?1914), pioneer aviator
• Sir Adrian Boult (1889?1984), conductor
• Edgar Adrian (1889?1977), scientist and Nobel Prizewinner
• Oliver Lyttelton, 1st Viscount Chandos (1893?1972), Cabinet Minister during World War II, chaiman of the National Theatre Board

20th century

• Gregory Dix (1902?1952), liturgical scholar
• Patrick Hamilton (1904?1962), novelist and playwright
• Sir John Gielgud (1904?2000), actor and director
• Sir John Aitken (1910?1985), Conservative newspaper owner
• H. A. R. "Kim" Philby (1912?1988), agent who defected to USSR 1963
• Professor Sir Richard Doll, CH FRS (1912?2005), epidemiologist
• Sir Richard Stone (1913?1991), Nobel prizewinner
• Angus Wilson (1913?1991), novelist
• Norman Parkinson (1913?1990), photographer
• Sir William Deakin (1913?2005), historian and literary assistant to Winston Churchill
• John Freeman (born 1915), Labour politician, broadcaster, diplomat and television chairman
• Sir Andrew Huxley FRS (born 1917), scientist
• Cecil Gould (1918?1994), art historian
• Brian Urquhart (born 1919) UN undersecretary-general and pioneer of peacekeeping
• Sir Peter Ustinov (1921?2004), actor, writer and director
• Michael Flanders and Donald Swann (1922?1975 and 1923?1994), performers, writers and musicians
• Neville Sandelson (1923?2002), founder member of the SDP
• Michael Havers (1923?1992), lord chancellor
• Richard Wollheim (1923?2003), philosopher
• Michael Hamburger (1924?2007), literary critic
• Colin Turnbull (1924?1994), anthropologist
• Tony Benn (born 1925), politician
• Peter Brook (born 1925), theatre director
• Tristram Cary (born 1925), composer
• Anthony Sampson (1926?2004) , author, founder member of the SDP
• Sir Crispin Tickell (born 1930), environmentalist, diplomat and academic
• Nigel, Lord Lawson (born 1932), former Conservative Chancellor of the Exchequer
• Anthony Howard (born 1934), journalist
• Sir Roger Norrington (born 1934), musician
• Simon Gray (born 1936), playwright
• William Cookson (1939?2004), literary critic
• Julian, Lord Hunt,(born 1942), climate change authority and Labour peer
• Peter Bottomley (born 1944), Conservative politician
• Peter Asher and Gordon Waller (born 1944 and 1945), musicians
• William, Baron Bach (born 1946), Labour politician
• Andrew, Lord Lloyd-Webber (born 1948), musician and producer
• Martin Amis (born 1949), novelist
• Michael Attenborough (born 1950), theatre director
• Tim Sebastian (born 1952) , television correspondent and interviewer
• Stephen Poliakoff (born 1952), playwright
• Robbie Fields (born 1952), record producer
• Nigel Planer (born 1953), novelist and actor
• Chris Huhne (born 1954), Liberal Democrat politician
• Adam Mars-Jones (born 1954), novelist and critic
• James Robbins (born 1955), diplomatic correspondent
• Tim Gardam (born 1955), journalist and educator, former director of Channel 4
• Andrew Graham-Dixon (born 1956), broadcaster and art historian
• Dominic Grieve (born 1956), shadow Attorney-General
• Dominic Lawson (born 1956), journalist
• Shane McGowan (born 1957), musician
• James Lasdun (born 1957), novelist
• Thomas Dolby (born 1958), musician
• Nigella Lawson (born 1960), broadcaster
• Edward St Aubyn (born 1960), author
• Tom Holt (born 1960), novelist
• Timothy Winter (born 1960), islamic scholar
• Michael Reiss (born 1960), anglican bioethicist
• George Benjamin (born 1960), composer
• Imogen Stubbs (born 1961), actress
• Matt Frei (born 1963), foreign correspondent
• Ian Bostridge (born 1964), tenor singer
• Helena Bonham Carter (born 1966), actress
• Noreena Hertz (born 1967), economist and author
• Gavin Rossdale (born 1967), musician and actor
• Julian Anderson (born 1967), composer
• Nick Clegg (born 1967), Liberal Democrat leader
• Richard Harris (born 1968), composer and pianist
• Ruth Kelly MP (born 1968), former Education Secretary
• Adam Buxton and Joe Cornish (born 1968 and 1969), TV performers and journalists
• Marcel Theroux (born 1969), novelist
• Louis Theroux (born 1970), broadcaster
• Tobias Hill (born 1970), poet and novelist
• Dido Armstrong (born 1971), musician under the name of "Dido"
• Martha Lane Fox (born 1973), dot.com entrepreneur
• James Reynolds (born 1974), BBC Beijing Correspondent
• Conrad Shawcross (born 1977), artist
• Christian Coulson (born 1978), actor
• Pinny Grylls (born 1978), filmmaker
• Benjamin Yeoh (born 1978), playwright
• James Brandon (born 1980), journalist
• Clemency Burton (born 1981),writer and actress
• Alice Eve (born 1982), actress
• Mica Penniman (born 1983), musician under the name "Mika"
• Max Vergara Poeti (born 1983), novelist and essayist

Footnotes