John Corcoran may refer to:John Corcoran (1842–1919), American soldier who received the Medal of Honor for valor during the American Civil War Jack Corcoran (1858–1935), American catcher in Major League Baseball John Corcoran (baseball) (1873–1901), American infielder in Major League Baseball John H. Corcoran (1897–1945), Massachusetts politician who served as the mayor of Cambridge, Massachusetts John Corcoran (author), American author and spokesman for literacy programs, who set up his own foundation to help people learn to read John Corcoran (logician) (1937–2021), American philosopher and logician, University at Buffalo (SUNY) John Corcoran (1948–2019), American non-fiction book author, newsstand magazine editor, screenwriter and martial arts historian John Corcoran (1959–2016), Irish Gaelic games administrator John Corcoran, Irish hurler and Gaelic footballer John Corcoran, British man convicted of the murder of Helen Gorrie and then released on appeal in contentious circumstances John Corcoran (attorney), former Clinton White House aide, former speechwriter in the California governor's office, attorney, and blogger