Events from the year 1771 in Great Britain.
- 22 January – Spain cedes the Falkland Islands to Britain.[2]
- 15 March – Society of Civil Engineers first meets (in London), the world's oldest engineering society.[3][4]
- 12 July – first voyage of James Cook (begun 1768): HMS Endeavour anchors in The Downs, and Captain Cook goes ashore at Deal, Kent, following his global circumnavigation.
- 8 August – first recorded town cricket match played at Horsham; Horsham Cricket Club formed here soon after 1806.[5]
- 17 August – Edinburgh botanist James Robertson makes the first recorded ascent of Ben Nevis.
- 30 September – Bath Assembly Rooms completed.
- 2 October – Prince Henry, Duke of Cumberland and Strathearn, brother to the King, marries a commoner, the widow Anne Horton, in Mayfair, precipitating the Royal Marriages Act 1772.
- 16 November – Several rivers flood in northern England, destroying many bridges and killing several people.[6][7]
Watson, Garth (1989). The Smeatonians: The Society of Civil Engineers. London: Thomas Telford. ISBN 978-0-7277-1526-5.
Roberts, Gwilym (1995). From Kendal's Coffee House to Great George Street. London: Thomas Telford. ISBN 978-0-7277-2022-1.
"Newcastle". Newcastle Courant. 23 November 1771. p. 2.