John Greer

John Greer may refer to:
 * John Greer, character in Person of Interest
 * John Greer (sculptor), Canadian sculptor
 * John W. Greer, Jr. (1909–1994), Georgia politician
 * John Alexander Greer (1802–1855), Texas politician
 * John Allen Greer (1874-1941), Tennessee politician
 * Big John Greer (1923–1972), American blues singer
 * John Michael Greer, American author