John Langdon Parsons, generally referred to as "J. Langdon Parsons", was a Cornish Australian politician, the 5th Government Resident of the Northern Territory, 1884-1890.
Parsons was born on 28 April 1837 at Botathan near Launceston, Cornwall.
He was instrumental in the development of railways in the Territory, and he also recognised Aboriginal land rights. Parsons was consul for Japan from 1896-1903. Member for the Central district in the South Australian Legislative Council, 1901-1903 as a National Defence League member.
Member of the South Australian House of Assembly for Encounter Bay, 1878 to 1881, and North Adelaide 1881 to 1884, Minister of education from 1881-1884.