William M'Intosh

William Carmichael M'Intosh FRSE FRS FLS (also spelt McIntosh; 10 October 1838, St Andrews – 1 April 1931, St Andrews) was a Scottish physician and marine zoologist. He served as president of the Ray Society, as vice-president of the Royal Society of Edinburgh (1927–30), and was awarded the Neill Prize (1865-8).

His medical qualification (LRCSE) was granted in 1860 by the Royal College of Surgeons of Edinburgh, following study at Edinburgh University.

McIntosh worked initially as an asylum doctor and was Director of the Perthshire District Asylum at Murthly for eighteen years. He later became a renowned botanist and marine biologist, travelling on HMS Challenger during the Challenger expedition of 1872 to 1876. He was Professor of Natural History at St Andrews University from 1882 to 1917, succeeded by D'Arcy Wentworth Thompson. He was also Director of the University Museum and was the first director of the University's Gatty Marine Laboratory (founded 1896). McIntosh was also a Fellow of the Linnean Society of London, a Fellow of the Royal Society of Edinburgh, and a Corresponding Member of the Zoological Society. He was elected a Fellow of the Royal Society in 1877, and was awarded the Royal Society's Royal Medal in 1899: "For his important monographs on British marine zoology and on the fishing industries." He received the honorary degree Doctor of laws (LL.D.) from the University of St Andrews in 1900, and was awarded the Linnean Medal in 1924.