Thomas Nicol Johnston FRSE (1870–1923) was a Scottish physician and noted amateur zoologist.
He was the son of Wilhelmina Storrie (1836–1903) and Thomas Johnston (1822–1899) of Corstorphine House in western Edinburgh.
He studied medicine as a mature student at the University of Edinburgh beginning in 1897. He graduated with an MB ChB.[1] From 1902 to 1907 he acted as the zoologist on John Murray and Laurence Pullar's Bathymetrical Survey of the Scottish Fresh-Water Lochs.[2] In 1903 he was elected a Fellow of the Royal Society of Edinburgh. His proposers were Sir John Murray, Laurence Pullar, Alexander Buchan and John Horne.[3]
He died at Humbie in East Lothian on 6 October 1923 but is buried with his parents in Corstorphine Parish Churchyard in western Edinburgh.[4]
He was married to Emma McPherson (1876-1953).
In 1917 he appears to have been involved in an antenuptial contract relating to the mental health of his daughter, Margaret Fraser Johnston to Charles Henry Adamson.[5]