Charles Johnston (17 February 1867 – 16 October 1931) was an Irish writer, journalist, theosophist, naturalist, and Sanskrit scholar.
Johnston joined the Indian Civil Service in 1888 but left India after two years due to malaria and settled in the United States in 1896.
He was married to the niece of Madame Blavatsky and was involved in the development of the Theosophical Society in the United States.
In 1884, he read Alfred Percy Sinnett's work The Occult World and founded, together with Yeats and Russell on 16 June 1885, the Hermetic Society in Dublin.
[10] He influenced several young ornithologists including Ludlow Griscom (whose father was involved in the Theosophical movement) and Joseph Hickey, both of the Bronx County Bird Club.