Surgeon-Captain John Ernest Trask (27 October 1861 – 25 July 1896) was an English Army doctor and amateur cricketer. He served in the Army Medical Services from 1887 until his death from cholera in Sudan during 1896. He was posthumously mentioned in dispatches, in which he was praised his role in managing the cholera outbreak. He is thought to have been referred to in Sir Arthur Conan Doyle's 1918 work The New Revelation, as a spirit Doyle converses with.