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