John Borthwick Gilchrist (19 June 1759 – 9 January 1841) was a Scottish surgeon, linguist, philologist and Indologist.
Born and educated in Edinburgh, he spent most of his early career in India, where he made a study of the local languages.
In later life, he returned to Britain and lived in Edinburgh and London.
In his final years, he moved to Paris, where he died at the age of 81.
He is principally known for his study of the Hindustani language, which led to it being adopted as the lingua franca of northern India (including present-day Pakistan) by British colonists and indigenous people.
He compiled and authored An English-Hindustani Dictionary, A Grammar of the Hindoostanee Language, The Oriental Linguist, and many more.
His lexicon of Hindustani was published in Arabic script, Nagari script, and in Roman transliteration.
He is also known for his role in the foundation of University College London and for endowing the Gilchrist Educational Trust.