Ponsonby may refer to:
Surname:
- Arthur Ponsonby, 1st Baron Ponsonby of Shulbrede (1871–1946), British politician, writer, and social activist
- Arthur Ponsonby, 11th Earl of Bessborough (1912–2002), British peer
- Ashley Ponsonby DL, JP (1831–1898), British Liberal politician
- Bernard Ponsonby, Scottish broadcast journalist
- Brabazon Ponsonby, 1st Earl of Bessborough (1679–1758), British politician and peer
- Lady Caroline Ponsonby (1785–1828), married name Lady Caroline Lamb, novelist and the lover of Lord Byron
- Cecil Ponsonby (1889–1945), English cricketer, right-handed batsman and wicket-keeper
- Chambré Brabazon Ponsonby (1720–1762), Irish Member of Parliament
- Chambré Brabazon Ponsonby-Barker (1762–1834), Irish Member of Parliament
- Sir Charles Ponsonby, 1st Baronet (1879–1976), British Conservative politician, Member of Parliament 1935–1950
- Charles Ponsonby, 2nd Baron de Mauley of Canford (1815–1896), British peer and Liberal politician
- Edward Ponsonby, 8th Earl of Bessborough, KP, CB, CVO (1851–1920), British peer
- Frederick Ponsonby, 10th Earl of Bessborough (1913–1993), British diplomat, businessman, playwright, Conservative politician and peer
- Frederick Ponsonby, 1st Baron Sysonby GCB GCVO PC (1867–1935), British soldier and courtier
- Frederick Ponsonby, 3rd Earl of Bessborough (1758–1844), British peer
- Frederick Ponsonby, 4th Baron Ponsonby of Shulbrede (born 1958), British peer and Labour politician
- Frederick Ponsonby, 6th Earl of Bessborough (1815–1895), a founder of Surrey County Cricket Club and I Zingari
- Frederick Ponsonby, 1st Baron Sysonby (1867–1935), British politician
- Major-General Sir Frederick Cavendish Ponsonby (1783–1837), British military officer
- Frederick Ponsonby, Viscount Duncannon (born 1974), British courtesy viscount
- George Ponsonby (Junior Lord of the Treasury) (1773–1863), Irish politician
- George Ponsonby (1755–1817), Lord Chancellor of Ireland
- Henrietta Ponsonby, Countess of Bessborough (1761–1821), wife of Frederick Ponsonby, 3rd Earl of Bessborough, mother of Lady Caroline Lamb
- Henry Ponsonby (died 1745) (1685–1745), Irish soldier
- Sir Henry Ponsonby (1825–1895), Private Secretary to Queen Victoria
- Joe Ponsonby (1876 – unknown), Irish footballer
- John Ponsonby (British Army officer) (1866–1952), commanded 5th Division during World War I
- Hon. John Ponsonby (politician) (1713–1789), Speaker of the Irish House of Commons
- John Ponsonby, 4th Earl of Bessborough (1781–1847), British politician and Lord Lieutenant of Ireland
- John Ponsonby, 5th Earl of Bessborough (1809–1880), British peer and politician
- John Ponsonby, 1st Viscount Ponsonby of Imokilly, (c.1772–1855), British diplomat
- John Maurice Maynard Ponsonby, Air Vice-Marshal
- Loelia Ponsonby (married name Loelia Lindsay) (1902–1993), British peeress, needlewoman and magazine editor
- Myles Ponsonby, 12th Earl of Bessborough (born 1941), British peer
- Myles Ponsonby CBE (1924–1999), British soldier, intelligence officer, diplomat and politician
- The Rt. Rev. Richard Ponsonby (1722–1815), Bishop of Derry and Raphoe
- Roberte Ponsonby, Countess of Bessborough (1892–1979), the daughter of Baron Jean de Neuflize, CVO
- Rupert Ponsonby, 7th Baron de Mauley (born 1957), British peer
- Rowland Ponsonby Blennerhassett or Rowland Blennerhassett (Irish politician) KC, JP (1850–1913), Irish politician
- Thomas Ponsonby, 3rd Baron Ponsonby of Shulbrede (1930–1990), British Labour Party politician
- Vere Ponsonby, 9th Earl of Bessborough (1880–1956), British Conservative Party politician, Governor General of Canada
- Walter Ponsonby, 7th Earl of Bessborough (1821–1906), British peer and member of the House of Lords
- William Ponsonby (British Army officer) KCB (1772–1815), Irish politician and British Army officer killed at the Battle of Waterloo
- William Ponsonby (publisher) (died 1604), London publisher of the Elizabethan era
- William Ponsonby, 1st Baron Ponsonby of Imokilly (1744–1806), leading Whig politician
- Major-General Sir William Ponsonby (general) (1772–1815), British cavalry commander killed at Waterloo
- William Ponsonby, 1st Baron de Mauley (1787–1855), British peer and Whig politician
- William Ponsonby, 2nd Earl of Bessborough, 2nd Earl of Bessborough PC PC (I) (1704–1793), British politician and public servant
Noble titles:
- Earl of Bessborough
- Viscount and Baron Ponsonby of Imokilly
- Baron de Mauley
- Baron Ponsonby of Shulbrede
- Baron Sysonby
Given name:
- Charles Garrett Ponsonby Moore, 11th Earl of Drogheda, 11th Earl of Drogheda KG, KBE (1910–1989), British peer
- Henry Dermot Ponsonby Moore, 12th Earl of Drogheda (born 1937), British photographer known professionally as Derry Moore
- Maurice Arthur Ponsonby Wood (1916–2007), Anglican bishop in the Evangelical tradition
- Nicholas Hickman Ponsonby Bacon (born 1953), British landowner, businessman and philanthropist
- Ponsonby Ogle (1855–1902), British writer and journalist
- Robert Ponsonby Staples (1853–1943), 11th Baronet of Lissan House near Cookstown in Co. Tyrone
- Robert Ponsonby Tottenham Loftus, Irish Anglican Bishop in the first half of the 19th century
- Rowland Ponsonby Blennerhassett (1850–1913), Irish politician
- Stephen Ponsonby Peacocke (1813–1872), British officer of the Bombay Army and an artist
Places:
- Ponsonby, Cumbria, England
- Ponsonby Fell, hill in the west of the English Lake District, near Gosforth, Cumbria
- Ponsonby, New Zealand
- Ponsonby (New Zealand electorate), parliamentary electorate in Auckland, New Zealand from 1887 to 1890 and from 1946 to 1963
- Ponsonby, Quebec, Canada – renamed to Boileau in 1993
- Ponsonby, Ontario, ghost town in Ontario, Canada
Other:
- Reginald Ponsonby-Smythe, Commander of Majestic-16 in Destroy All Humans! 2
- Ponsonby (soccer), former New Zealand football club, now amalgamated to form Mount Albert-Ponsonby
- Ponsonby Ponies, rugby league club based in Ponsonby, New Zealand
- Ponsonby RFC, rugby union club based in Auckand, New Zealand
- Mr Ponsonby, the fourth novel by New Zealand author Ian Middleton
- Ponsonby Britt, the fictional executive producer of TV series including The Rocky and Bullwinkle Show
- Ponsonby Rule, constitutional convention in the UK constitutional law involving 21 days' notice for international treaties