John Harris may refer to:
United Kingdom
- John Harris (MP for Hampshire) (died 1429), English MP for Hampshire 1415
- John Harris (MP for Grampound), English MP for Grampound, 1555
- John Harris (MP for West Looe) (c. 1564–1623), English MP for West Looe, 1614
- John Harris (MP for Montgomery) (died 1626), MP for Montgomery, 1601
- John Harris (Bere Alston MP) (1586–1657), English MP for Bere Alston and Launceston
- John Harris (Royalist) (1596–1648), English MP for Liskeard, 1628, 1640, 1644
- John Harris (died 1677) (1631–1677), English MP for Liskeard
- John Harris (merchant), British Member of Parliament for Exeter, 1708
- John Harris (courtier) (died 1767), British Member of Parliament for Ashburton
- John Harris (1703–1768), British Member of Parliament for Barnstaple
- John Harris (Bristol) (1725–1801), English merchant who was Mayor of Bristol in 1790
- John Dove Harris (1809–1878), English Liberal politician
- John Harris (engineer) (1812–1869), railway engineer of the Stockton and Darlington Railway 1836–47.
- John Harris (anti-slavery campaigner) (1874–1940), English missionary, campaigner against slavery, and Liberal Party politician
- John Harris, Baron Harris of Greenwich (1930–2001), British political aide and politician for Labour and Liberal Democrats
- John Quincey Harris (1815–1846), British Whig politician
- John Harris (Warden) (1588–1658), English academic, clergyman, Warden of Winchester College
- John Harris (college head) (1802–1856), Congregational minister and college president
- John Howard Harris (1847–1925), president of Bucknell University, 1889–1919
- John Harris (bioethicist) (born 1945), professor of bioethics and think tank director
- John Harris (physicist) (born 1950), physics professor at Yale University
- John R. Harris (1934–2018), professor of economics at Boston University
- John Harris (phonologist), Irish linguist
- John Harris (psycholinguist), Irish linguist
- John Harris (biblical scholar), Australian biblical scholar and creolist
- John Harris Sr. (1673–1748), trader who settled and established Harrisburg, Pennsylvania
- John Harris (surveyor) (died 1772), farmer, land surveyor and political figure in Nova Scotia
- John Harris Jr. (settler) (1716–1791), American storekeeper and frontiersman
- John Williams Harris (1808–1872), New Zealand trader, whaler, and farmer
- John Harris (manufacturer) (1841–1887), Canadian businessman and manufacturer
- John P. Harris (1871–1926), Pittsburgh businessman
- John C. Harris (born 1943), owner of Harris Farms
- John Harris (writer) (1666–1719), English writer, scientist, and Anglican priest
- John Harris (spinet maker) (died 1772), Boston maker of spinets and harpsichords
- John Harris (publisher) (1756–1846), English bookseller and printseller
- John Harris Jr. (artist) (1791–1873), English artist
- John Harris (poet) (1820–1884), Cornish poet
- John H. Harris (entertainment) (1898–1969), American, first owner of the Ice Capades
- John Harris (novelist) (1916–1991), British author
- John Harris (curator) (1931–2022), English author, architectural historian
- John Harris (artist) (born 1948), painter and illustrator known for his science-fiction work
- John T. Harris (artist) (1908–1972), painter, printmaker, educator
- John Harris (critic) (born 1969), music and politics journalist
- John F. Harris (born 1960s), author and writer for Politico.com
- John Wyndham (John Wyndham Parkes Lucas Beynon Harris, 1903–1969), English science fiction author
- John Harris (software developer), computer programmer of Atari computer games
- John Harris (Australian footballer) (1903–1993), former VFL player with Collingwood
- John Harris (footballer, born 1917) (1917–1988), Scottish footballer and manager
- John Harris (footballer, born 1939) (1939–2023), English footballer
- John Harris (Irish footballer), Northern Irish footballer and cricketer
- John Harris (defensive back) (born 1933), former American football cornerback
- John Harris (safety) (born 1955), former American football safety
- John Harris (wide receiver) (born 1991), American football player
- Tony Harris (footballer) (John Robert Harris, 1922–2000), Scottish footballer