Events from the year 1773 in Great Britain.
- 14 January – William Amherst, 1st Earl Amherst, ambassador to China and Governor-General of India (died 1857)
- 27 January – Prince Augustus Frederick, Duke of Sussex (died 1843)
- 6 April – James Mill, historian, economist, political theorist and philosopher (died 1836)
- 19 May – Arthur Aikin, chemist and mineralogist (died 1854)
- 13 June – Thomas Young, physicist (died 1829)
- 23 July – Thomas Brisbane, Scottish astronomer and Governor of New South Wales (died 1860)
- 23 October – Francis Jeffrey, Lord Jeffrey, judge and literary critic (died 1850)
- 28 October – Simon Goodrich, mechanical engineer (died 1847)
- 6 November – Henry Hunt, politician (died 1835)
- 21 December – Robert Brown, botanist (died 1858)
- 27 December – George Cayley, aviation pioneer (died 1857)
- 9 February – John Gregory, physician, medical writer and moralist (born 1724)
- 24 March – Philip Dormer Stanhope, 4th Earl of Chesterfield, statesman and man of letters (born 1694)
- 15 May – Alban Butler, Catholic priest and writer (born 1710)
- 23 July – George Edwards, naturalist (born 1693)
- 24 August – George Lyttelton, 1st Baron Lyttelton, politician (born 1709)
- 7 November – Andrew Brice, printer and writer (born 1690)
- 15 November – Bernard Gates, composer (born 1686)
- 16 November – John Hawkesworth, writer (born c. 1715)
- 20 November – Charles Jennens, landowner (born c. 1700)
Palmer, Alan; Palmer, Veronica (1992). The Chronology of British History. London: Century Ltd. pp. 226–227. ISBN 0-7126-5616-2.