Academics

• John Smith (anatomist and chemist) (1721–1797), professor of anatomy and chemistry at the University of Oxford, 1766–1797
• John Blair Smith (1764–1799), president of Union College, New York
• John Smith (Cambridge, 1766), vice chancellor of the University of Cambridge, 1766 until 1767
• John Smith (astronomer) (1711–1795), Lowndean Professor of Astronomy and Master of Caius
• John Smith (professor of languages) (1752-1809), professor of languages at Dartmouth College
• John Augustine Smith (1782–1865), president of the College of William and Mary, 1814–1826
• John Smith (botanist) (1798–1888), curator of Kew Gardens
• John Smith (physician) (c.1800–1879), Scottish physician specialising in treating the insane
• John Alexander Smith (physician) (1818–1883), Scottish physician, antiquarian, archaeologist and ornithologist
• J. Lawrence Smith (chemist) (1818–1883), American doctor and chemist
• John Smith (dentist) (1825–1910), founder of Edinburgh's School of Dentistry
• John Campbell Smith (1828–1914), Scottish writer, advocate and Sheriff-Substitute of Forfarshire
• John Donnell Smith (1829–1928), biologist and taxonomist
• John McGarvie Smith (1844–1918), Australian metallurgist and bacteriologist
• John Bernhardt Smith (1858–1912), American entomologist
• John Alexander Smith (1863–1939), British Idealist philosopher
• John Maynard Smith (1920–2004), geneticist
• John Cyril Smith (1922–2003), leading authority on English criminal law
• John Derek Smith (1924–2003), Cambridge molecular biologist
• John Smith (sociologist) (1927–2002), English sociologist
• John D. Smith (born 1946), indologist at the University of Cambridge
• John H. Smith (mathematician), Boston College educator (retired 2005)
• John E. Sharwood Smith, English professor of classics
• John Edwin Smith, American philosopher
• John Merlin Powis Smith, English-born, American orientalist and biblical scholar

Arts

• John Smith (engraver) (1652–1742), English mezzotint engraver
• John Smith (English poet) (1662–1717), English poet and playwright
• John Christopher Smith (1712–1795), English composer
• John Warwick Smith (1749–1831), British watercolour landscape painter and illustrator
• John Stafford Smith (1750–1836), composer of the tune for "The Star-Spangled Banner"
• John Raphael Smith (1751–1812), English mezzotint engraver and painter
• John Thomas Smith (engraver) (1766–1833), draughtsman, engraver and antiquarian
• John Smith (clockmaker) (1770–1816), Scottish clockmaker
• John Rubens Smith (1775–1849), London-born painter, printmaker and art instructor who worked in the United States
• John Smith (architect) (1781–1852), Scottish architect
• John Smith Murdoch (1862–1945), Scottish architect
• John Smith (art historian) (1781–1855), British art dealer
• John Orrin Smith (1799–1843), English wood engraver
• John Frederick Smith (1806–1890), English novelist
• John Rowson Smith (1810–1864), American panorama painter
• John Kelday Smith (1834–1889), Scottish bellhanger and songwriter
• John G. Smith (poet) (died 1891), Scottish poet
• John Moyr Smith (1839–1912), British artist and designer
• John Berryman (1914–1972), originally John Allyn Smith, American poet
• John Smith (Canadian poet) (1927–2018), Canadian poet
• John Smith (actor) (1931–1995), American actor
• John N. Smith (born 1943), Canadian film director and screenwriter
• John Smith (English filmmaker) (born 1952), avant-garde filmmaker
• John Warner Smith (born 1952), American poet and educator
• John F. Smith, American soap opera writer and producer
• John Smith (comics writer) (born 1967), British comics writer
• John Smith (folk musician), English contemporary folk musician and recording artist
• John F. Smith (musician) (born 1950), British musician and trade unionist
• John Smith (comedian), British comedian, actor and performer

Business

• John Smith (banker) (1797–1866), Scottish banker and philanthropist, working in England
• John K. Smith (died 1845), founder of SmithKline as in GlaxoSmithKline, the leading pharmaceutical business
• John Russell Smith (1810–1894), English bookseller and bibliographer
• John J. Smith (1820–1906), African-American abolitionist, Underground Railroad contributor and politician
• John Smith (brewer) (1824–1879), Tadcaster brewery founder in North Yorkshire, UK
• John L. Smith (pharmaceutical executive) (1889–1950), German-born American chemist, pharmaceutical executive and Major League Baseball team owner
• John F. Smith Jr. (born 1938), former chairman and chief executive officer, General Motors
• John Smith (executive) (born 1957), former chief executive officer, BBC Worldwide Ltd

Crime

• John Smith (housebreaker) (1661–after 1727), London housebreaker who evaded hanging thrice and was eventually transported to Virginia
• John Smith (died 1835) (1795–1835), one of the last two Englishmen who were hanged for sodomy in 1835
• John Eldon Smith (1930–1983), convicted of the murders of Ronald and Juanita Akins
• John Smith (murderer) (born 1951), American convicted murderer who killed his first and second wives

Law

• John Gordon Smith (surgeon) (1792–1833), Scottish surgeon and professor of medical jurisprudence
• John Sidney Smith (legal writer) (1804–1871), English legal writer
• John William Smith (legal writer) (1809–1845), English barrister and legal writer
• John Smalman Smith, (1847-1914) British judge in the Colony of Lagos
• John Lewis Smith Jr. (1912–1992), United States federal judge
• John Smith (police officer) (born 1938), British police officer, Deputy Commissioner of the Metropolitan Police, 1991–1995

Military

• John Smith (banneret) (1616–1644), Englishman who supported the Royalist cause in the English Civil War
• John Smith (British Army officer, born 1754) (1754–1837), soldier in the American Revolutionary War
• John Smith (naval officer) (1780–1815), United States Navy officer, who served during the First Barbary War and later in the War of 1812
• Frederick Smith (British Army officer, born 1790) (John Mark Frederick Smith, 1790–1874), British general and colonel-commandant of the Royal Engineers
• John Smith (sergeant) (1814–1864), soldier in the Bengal Sappers and Miners, and Indian Mutiny Victoria Cross recipient
• John E. Smith (1816–1897), Swiss emigrant, Union general during the Civil War
• John Smith (private) (1822–1866), soldier in the 1st Madras (European) Fusiliers and Indian Mutiny Victoria Cross recipient
• John Smith (Medal of Honor, born 1826) (1826–1907), American Civil War sailor and Medal of Honor recipient
• John Smith (Medal of Honor, born 1831) (1831–?), American Civil War sailor and Medal of Honor recipient
• John Smith (Medal of Honor, born 1854) (1854–?), United States Navy sailor and Medal of Honor recipient
• John Manners Smith (1864–1920), recipient of the Victoria Cross
• John Smith (flying ace) (1914–1972), United States Marine Corps flying ace and Medal of Honor recipient

Politicians

Religion

• John Smith (bishop of Llandaff) (died 1479), Welsh bishop
• John Smith (Platonist) (1618–1652), one of the founders of the Cambridge Platonists
• John Smith (bishop of Killala and Achonry) (died 1680), Irish Anglican priest
• John Smith (Unitarian) (fl. 1648–1727), Unitarian writer
• John Smith (priest, born 1659) (1659–1715), English editor of Bede
• John Smith (uncle of Joseph Smith) (1781–1854), Presiding Patriarch and member of the First Presidency of the Church of Jesus Christ of Latter-day Saints
• "Raccoon" John Smith (Restoration Movement) (1784–1868), early Restoration Movement leader
• John Smith (missionary) (1790–1824), English missionary in Demerara
• John Smith (priest, born 1799) (1799–1870), first person to transcribe the Diary of Samuel Pepys
• John Smith (nephew of Joseph Smith) (1832–1911), Presiding Patriarch of the Church of Jesus Christ of Latter-day Saints
• John Henry Smith (1848–1911), apostle in the Church of Jesus Christ of Latter-day Saints
• John Smith (moderator) (1854-1927), moderator of the General Assembly of the Church of Scotland in 1922
• John Taylor Smith (1860–1938), Anglican bishop of Sierra Leone
• John Smith (archdeacon of Llandaff), Welsh Anglican priest
• John Smith (archdeacon of Wiltshire) (1933–2000), Anglican priest
• John M. Smith (bishop) (1935–2019), American Roman Catholic bishop
• John H. Smith (bishop) (1939–2012), American Episcopal prelate, Bishop of the Episcopal Diocese of West Virginia, 1989–1999
• John Smith (God's Squad) (died 2019), Australian founder of the God's Squad motorcycle club

Sports

Other

• Sir John Smith, 1st Baronet (1744–1807), baronet
• John Kilby Smith (1752–1842), public servant from New England
• John Smith (Chippewa Indian) (died 1922), reputed to have died at the age of 137
• John Smith (abolitionist), 19th century American industrialist and abolitionist
• John Chaloner Smith (1827–1895), Irish civil engineer and writer on mezzotints
• John Brown Smith (1837–?), American author, shorthand developer, utopianist, tax resister
• John Baptist Smith (1843–1923), invented and helped build a lantern system of naval signaling
• J. E. Smith (c. 1862/1863–1912), English trade union leader
• John Chabot Smith (1915–2002), American journalist and author
• John Douglas Smith (born 1966), sound editor
• John Henry Smith (reporter), American sports journalist, active 2000s
• John Smith (Australian journalist), Australian journalist, winner of 2016 Kennedy Award