John Johnstone ( - 1794) was a 1st lieutenant in the 39th (Plymouth) Company when he arrived at Sydney aboard the Alexander in January 1788 as part of the First Fleet.
Johnstone was sent to Norofolk Island on the Sirius in March 1790 where he as appointed adjutant general. After falling ill he was sent back to Port Jackson on the Supply in February 1791 and returned to England on the Gorgon in December 1791. He died on 29 November 1794.
* information from Mollie Gillen, The Founders of Australia: A Biographical Dictionary of the First Fleet (1989), p 197
'Johnstone, John (?–1794)', People Australia, National Centre of Biography, Australian National University, https://peopleaustralia.anu.edu.au/biography/johnstone-john-31382/text38830, accessed 11 May 2025.