John Fay may refer to: John Fay (American football) (1895–1983), American football player John D. Fay (1815–1895), American civil engineer John Fay (politician) (1773–1855), American politician John J. Fay Jr. (1927–2003), American politician in New Jersey John Fay (writer) (21st century), British television writer John David Fay, mathematician, eponym of Fay's trisecant identity