William Marcet FRS FRCP (13 May 1828 – 4 March 1900) was President of the Royal Meteorological Society He was born the son of Francis Marcet, FRS and the grandson of Alexander Marcet, FRS in Geneva, Switzerland. He graduated M.D. as a physician from Edinburgh University in 1850 with the thesis "Fermentation". He was elected a Fellow of the Royal Society in 1857. He was President of the Royal Meteorological Society from 1888 to 1889. He died in London.