John Mather may refer to:
Authors and academics John Mather (academic) (before 1680–after 1748), English administrator at University of Oxford John Mather (artist) (1848–1916), Australian landscape painter and art teacher John Baxter Mather (1853–1940), Scottish-born newspaper proprietor, painter and art critic in South Australia John N. Mather (1942–2017), American mathematician at Princeton John C. Mather (born 1946), American Nobel Prize–winning astrophysicist and cosmologist
Businessmen John Mather (businessman) (1827–1907), Canadian pioneer in milling John T. Mather (1854–1928), American industrialist and philanthropist
Politicians John C. Mather (New York politician) (1813–1882), American state legislator and commissioner John Perkins Cushing Mather (1816–1891), American state legislator and judge in Connecticut John B. Mather (c.1845–1892), Canadian businessman and alderman in Winnipeg
Others John Mather (cricketer) (1821–1870), English-born Australian first-class player for Victoria John Eugene Mather (1907–1966), American radio, film and TV actor, stage name Jack Mather
See also John Mathers, Blue Paint Killer on 2002 List of CSI: Crime Scene Investigation characters#Adversaries