Lyon is the surname of:
- A. Laurence Lyon (1934–2006), American music composer
- Alexander Lyon (disambiguation)
- Alastair Lyon (born 1979), South African rugby player
- Anne Bozeman Lyon (1860-1936), American writer
- Arthur Lyon (disambiguation)
- Asa Lyon (1763–1841), American politician
- Babe Lyon (1907–1970), American football player
- Barbara Lyon (1931–1995), American-born singer who lived and worked mostly in England
- Barrett Lyon (born 1978), American computer entrepreneur
- Ben Lyon (1901–1979), American film actor
- Beverley Lyon (1902–1970), British cricketer
- Bill Lyon (1886–1962), Australian football player
- Billy Lyon (born 1973), American football player
- Bob Lyon (born 1955), American politician
- Brandon Lyon (born 1979), American baseball pitcher
- Bruce Lyon, American film producer
- Caleb Lyon (1822–1875), American politician, governor of Idaho Territory
- Charles Lyon (1878–1959), British cricketer
- Charles W. Lyon (1887–1960), American politician
- Chittenden Lyon (1787–1842), American politician
- Christopher Lyon, American political consultant
- Daniel Lyon (born 1980), American professional wrestler
- Danny Lyon (born 1942), American photographer and filmmaker
- David Lyon (disambiguation)
- Dar Lyon (1898–1964), English cricketer
- Duffy Lyon (1929–2011), American farmer and butter sculptor
- Edward E. Lyon (1871–1931), US soldier and war hero
- Elinor Lyon (1921–2008), English author
- Francis D. Lyon (1905–1996), American film editor
- Francis Strother Lyon (1800–1882), American and Confederate States politician
- Frank Lyon (1867–1955), American lawyer, newspaper publisher and land developer
- Fred Lyon (1924–2022), American photographer
- Frederick A. Lyon (1843–1911), American Union Army soldier during the US Civil War, awarded the Medal of Honor
- Gail Lyon, American filmmaker
- Garry Lyon (born 1967), Australian rules footballer
- George Lyon (disambiguation)
- Gordon Lyon (born 1977), computer expert
- Gustave Lyon (1857–1936), French piano maker, acoustician and inventor
- Guy J. Lyon (1933–2001), US horse trainer
- Harris Merton Lyon (1882–1916), US author
- Harry Lyon (disambiguation)
- Hart Lyon (1721–1800), Chief Rabbi of the United Kingdom
- Homer L. Lyon (1879–1956), American politician
- Howard Lyon, American artist
- Hylan B. Lyon (1836–1907), Confederate general in the American Civil War
- Ivan Lyon (1915–1944), British Second World War lieutenant colonel
- James Lyon (disambiguation)
- Jamie Lyon (born 1982), Australian rugby league player
- Jason Lyon (born 1986), Canadian archer
- Jean Lyon, Countess of Strathmore and Kinghorne (1713–1778), British noblewoman
- Jennifer Lyon (1972–2010), American television actress
- Jimmy Lyon (born 1955), American rock musician
- Jo Anne Lyon (born 1940), American Methodist
- John Lyon (disambiguation)
- Joshua Lyon (born 1974), American author
- Juliet Lyon, director of Prison Reform Trust
- Leo De Lyon (1925–2021), American voice actor
- Lisa Lyon (1953–2023), American bodybuilder
- Lucius Lyon (1800–1851), American politician
- Lyon sisters, two teenagers who vanished in 1975
- Marcus Ward Lyon, Jr. (1875–1942), American mammalogist, bacteriologist, and pathologist
- Marion Jean Lyon (1885–1940), British advertising manager
- Mary Lyon (1797–1849), American pioneer in women's education
- Mary Lyon (writer), American author
- Mary F. Lyon (1925–2014), English geneticist
- Matthew Lyon (1749–1822), American politician
- Myer Lyon (1750–1797), German-born English singer
- Nathan Lyon (chef), American television personality and chef
- Nathan Lyon (cricketer) (born 1987), Australian cricketer
- Nathaniel Lyon (1818–1861), American Civil War general
- Nick Lyon (born 1970), American filmmaker
- Noah Lyon (born 1979), American artist
- P. H. B. Lyon (1893–1986), British poet and educator
- Peter Lyon (born 1941), Australian football player
- Phyllis Lyon (1924–2020), American feminist and gay-rights activist
- Richard Lyon (disambiguation)
- Rick Lyon (born 1958), American puppeteer
- Robert Lyon (disambiguation)
- Rod Lyon, British radio personality
- Ross Lyon (born 1966), Australian football player and coach
- Russ Lyon (1913–1975), American baseball player
- Sam Lyon (1890–1916), English footballer
- Sterling Lyon (1927–2010), premier of Manitoba
- Steve Lyon (born 1952), Canadian hockey player
- Sue Lyon, (1946–2019), American actress
- T. Edgar Lyon (1903–1978), American scholar
- Thomas Lyon (disambiguation)
- Tom Lyon, British escape artist
- Waldo K. Lyon (1914–1998), US Navy research scientist
- Walter Lyon (poet) (1887–1915), British war poet
- Walter Lyon (cricketer) (1841–1918), English cricketer
- Walter Lyon (Pennsylvania politician) (1853–1933), American politician
- William Lyon (film editor) (1903–1974), American film editor
- William Lyon (bishop) (died 1617), British cleric
- William Lyon (general) (1923-2020), US Air Force major general
- William C. Lyon (1841–1908), American politician, governor of Ohio
- William Durie Lyon (1825–1893), Canadian politician
- William P. Lyon (1822–1913), American politician