John Latham (27 June 1740 – 4 February 1837) was an English physician, naturalist and author. He was born in Eltham in South East London, and was the eldest son of John Latham (d.1788), a surgeon there, and his mother was a descendant of the Sothebys, in Yorkshire.
Latham has been called the "grandfather" of Australian ornithology. He was able to examine specimens of Australian birds which reached England in the last twenty years of the 18th century, and was responsible for naming many of them. These included the Emu, Sulphur-crested Cockatoo, Wedge-tailed Eagle, Superb Lyrebird, Sociable Weaver and Australian Magpie. He was also the first to describe the Hyacinth Macaw. Latham practiced as a physician at Dartford in Kent, where he collected the Dartford Warbler. He retired in 1796 and settled in Hampshire. His main works were A General Synopsis of Birds (1781–1801) and General History of Birds (1821–1828).
A General Synopsis of Birds was Latham's first ornithological work and contained 106 illustrations by the author. It described many new species which Latham had discovered in various museums and collections. In this work, like Georges-Louis Leclerc, Comte de Buffon, he did not attach importance to the names of the species which he described. Later, Latham realised that only the use of the Linnean binomial system would give him the honour of originating the species' scientific names. Thus he published in 1790, a Index Ornithologicus where he specified a binomial name for all the species which he had previously described. Unfortunately it was too late, as Johann Friedrich Gmelin had already published his own version of Linnaeus' Systema Naturæ in which he gave a scientific name to Latham's species; taking into account the rules of nomenclature, Gmelin has priority.
Latham maintained a regular correspondence with Thomas Pennant, Joseph Banks, Ashton Lever and others. He was elected to the Royal Society in 1775, and also took part in the creation of the Linnean Society. In 1812, he was elected a foreign member of the Royal Swedish Academy of Sciences.
The standard author abbreviation Latham is used to indicate this individual as the author when citing a zoological name.