John Henry Clarke (1853–1931) was an English classical homeopath who trained at the University of Edinburgh and built a successful practice in London, where he also served as consulting physician at the London Homeopathic Hospital. A longtime editor of The Homeopathic World, he wrote more than twenty books on homeopathic practice and was elected President of the British Homeopathic Society in 1906. The Prescriber, first published in 1885, remains one of his most widely used clinical references, organising remedies alphabetically by disease heading to guide practical prescribing.