Guinn is both a surname and a given name. Notable people with the name include: Surname:

• Bill Guinn or Lew Meehan (1890–1951), American film actor
• Colin Guinn, contestant in The Amazing Race, a U.S. TV series
• Dominick Guinn, (born 1975), American professional boxer
• Ernest Allen Guinn (1905–1974), United States federal judge
• Kenny Guinn (1936–2010), American businessman, educator and politician
• Nora Guinn (1920–2005), American judge
• Robert Henry Guinn (1822–1887), Texas politician
• Skip Guinn (born 1944), former Major League Baseball pitcher
• Thomas Guinn (1836–1908), Union Army soldier during the American Civil War

Given name:

• Guinn Smith (1920–2004), American athlete, 1948 Olympic champion in the pole vault
• Guinn Williams (actor) (1899–1962), American actor who appeared in memorable westerns
• Guinn Williams (Texas politician) (1871–1948), U.S. Representative from Texas

• Guinn Run, Pennsylvania stream flowing southeastward in the Gettysburg National Military Park
• Guinn v. United States, 238 U.S. 347 (1915), U.S. Supreme Court decision on state constitutions that set qualifications for voters
• Guinan (disambiguation)
• Guinea (disambiguation)
• Guinee
• Guiney