Guy is a French and English surname. Notable people with the surname include:

• Athol Guy (born 1940), Australian musician
• Barry Guy (born 1947), British composer
• Billy Guy (1936–2002), American singer
• Brent Guy (born 1960), American football coach
• Buddy Guy (born 1936), American guitarist
• Charles A. Guy (d. 1985), American newspaper owner and editor
• Charles H. Guy (1924–2010), American football and lacrosse player and coach
• Charles L. Guy (1856–1930), American politician and judge from New York
• Constantin Guys (1802–1892), French journalist
• Derek Guy, menswear writer
• Edna Guy (1907–1982), American dancer
• Edna Guy (artist) (1897–1969), British artist
• Étienne Guy (1774–1820), Canadian surveyor and politician
• Fabrice Guy (born 1968), French skier
• Frances Guy (born 1959) British former ambassador, UN Women's representative in Iraq
• Fred Guy (1897–1971), American jazz banjo player and guitarist
• Gary Guy (born 1952), Australian rules footballer
• Georgia Guy (born 1993), New Zealand cricketer
• Greg Guy (born 1971), American basketball player
• Henry Lewis Guy (1887–1956), British mechanical engineer
• James Guy (disambiguation)
• Jasmine Guy (born 1962), American actress
• Jean Guy (1922–2013), First Lady of North Dakota
• John Guy (governor) (died 1629), English merchant and Governor of Newfoundland
• John Guy (historian) (born 1949), British historian
• Kyle Guy (born 1997), American basketball player
• Lawrence Guy (born 1990), American football player
• Lewis Guy (born 1985), English footballer
• L. Ruth Guy (1913–2006), American educator and pathologist; Texas Women's Hall of Fame
• Mark Guy (born 1964), American football player
• Matthew Guy (born 1974), Australian politician
• Morais Guy, Jamaican politician
• Nathan Guy (born 1970), New Zealand politician
• P.L.O. Guy (1885–1952), British archaeologist
• Phil Guy (1940–2008), American guitarist
• Ray Guy (1949–2022), American football player
• Ray Guy (humorist) (1939–2013), Canadian journalist and writer
• Richard K. Guy (1916–2020), British mathematician
• Rosa Guy (1925–2012), American writer
• Scott Guy (died 2010), New Zealand murder victim
• Thomas Guy (1644–1724), British founder of Guy's Hospital
• Trent Guy (born 1987), American football player
• William Guy (1810–1885), British physician
• William L. Guy (1919–2013), American politician