John, Johnny, or Johnie Watson may refer to:

• John Watson (16th-century MP) (fl. 1547–1554), Member of Parliament for Morpeth, Newcastle upon Tyne and Berwick-upon-Tweed
• Sir John Watson (advocate) (John Charles Watson, 1883–1944), Scottish advocate and sheriff, Solicitor General for Scotland 1929–31
• John Watson (Australian politician) (born 1937), former Australian senator
• John Watson (Queensland politician) (1833–?), member of the Queensland Legislative Assembly
• John Watson (Skipton MP) (born 1943), British Member of Parliament for Skipton, 1979–1989
• John Watson (Virginia politician) (died 1870), African-American politician in Virginia
• John A. Watson, member of the California State Assembly
• Sir John Bertrand Watson (1878–1948), British Member of Parliament for Stockton-on-Tees, 1917–1923
• John C. Watson (judge) (1878–1970), justice of the New Mexico Supreme Court
• Chris Watson (John Christian Watson, 1867–1941), Australia's third prime minister
• John H. Watson (Vermont judge) (1851–1929), Vermont attorney and judge
• John Hampton Watson (1804–1883), American judge
• John S. Watson (New Jersey politician) (1924–1996), African-American Democratic Party politician in New Jersey
• John T. Watson (1908–2007), justice of the New Mexico Supreme Court
• J. W. Watson Sr. (1859–1942), Mayor of Miami and speaker of the Florida House of Representatives
• John William Clark Watson (1808–1890), Confederate politician and judge

• Sir John Watson (Indian Army officer) (1829–1919), English recipient of the Victoria Cross in 1857
• John C. Watson (admiral) (1842–1923), admiral of the United States Navy
• John Watson Tadwell Watson, British Army general

• Daddy Stovepipe (1867–1963), real name Johnny Watson, African-American blues singer
• Johnny "Guitar" Watson (1935–1996), American blues guitarist
• John M. Watson Sr. (1937–2006), American actor and musician
• John L. Watson (singer) (1941–2014), American singer who fronted English rock band The Web

• John Watson (American painter) (1685–1768), American portrait artist
• John Watson, later Sir John Watson Gordon (1788–1864), Scottish painter
• John Watson (English artist) (born 1971), English artist and comicbook artist
• John Dawson Watson (1832–1892), British painter, watercolorist, and illustrator

• John Watson (American football) (born 1949), former NFL offensive lineman
• John Watson (bowls) (born 1945), former Scottish lawn and indoor bowler
• John Watson (boxer) (born 1983), British lightweight boxer
• John Watson (cricketer, born 1828) (1828–1920), Australian cricketer who made one appearance for Tasmania
• John Watson (Somerset cricketer) (1910–1980), English cricketer who made 19 appearances for Somerset
• John Watson (curler) (c. 1914–1974), Canadian curler
• John Watson (cyclist) (born 1947), British Olympic cyclist
• John Watson (equestrian) (born 1952), Irish Olympic equestrian
• John Watson (footballer, born 1877) (1877–?), Scottish football player (Everton)
• John Watson (footballer, born 1942), football player (Chester City)
• John Watson (footballer, born 1959), football player (Fulham)
• John Watson (golfer), American golfer
• Sir John Watson (polo), British polo player
• John Watson (racing driver) (born 1946), British Formula One driver
• John Fox Watson (1917–1976), believed to be the only Scottish football player in Real Madrid's history
• Johnny Watson (baseball) (1908–1965), American baseball player
• Johnie Watson (1896–1958), American baseball player
• John L. Watson, American chess master

• Dr. Watson, fictional associate and biographer of detective Sherlock Holmes in Arthur Conan Doyle's stories
• John Watson, known as Wonko the Sane, character from the novel So Long, and Thanks For All the Fish by Douglas Adams

• John Watson (Master of Christ's College, Cambridge) (died 1537), priest, academic, and Vice-Chancellor of Cambridge University
• John Watson (bishop) (1520–c.1584), Bishop of Winchester
• John Watson (officer of arms), English 17th century Bluemantle Pursuivant
• John Watson (antiquary) (1725–1783), English clergyman and antiquary
• John Boles Watson (c.1748–1813), English theatre builder
• John Watson (priest) (1767–1839), English clergyman
• John Watson (Dean of Ferns), Irish Anglican priest
• John Watson (college president) (1771–1802), first president of Jefferson College, Pennsylvania
• John Fanning Watson (1779–1860), American antiquarian
• John Kippen Watson (1816–1891), improver of Edinburgh's gas lighting
• John Selby Watson (1804–1884), British classical translator and murderer
• John Forbes Watson (1827–1892), Scottish physician and writer on India
• John Watson (philosopher) (1847–1939), Canadian philosopher and academic
• John Watson (1850–1907), Scottish theologian and author who wrote under the pseudonym Ian Maclaren
• John Duncan Watson (1860–1946), British civil engineer
• John B. Watson (1878–1958), American psychologist; pioneer of behaviorism
• John Watson (1914–2007), known as Adam Watson, British international relations theorist and researcher, and ambassador
• John L. Watson (born 1951), American chess player and author
• John S. Watson (Chevron CEO) (born 1956), American businessman and former CEO of Chevron Corporation
• John Watson (activist) (died 2001), American black activist and editor
• John Watson (film producer), English film producer
• John Boyd Watson (1828–1889), Australian mining magnate and investor
• John Michael Watson, English botanist
• John Steven Watson (1916–1986), English historian and principal of the University of St Andrews
• Jack Watson (cattle station manager) (John Watson, 1852–1896), cattle station manager in Australia

• Jack Watson (disambiguation)
• Jonathan Watson, Scottish comedian and impressionist