Greenblatt or Greenblat (Yiddish: "green leaf") is a surname. Notable people with the surname include:
- Ariana Greenblatt (born 2007), American actress
- C. H. Greenblatt (born 1972), American writer and storyboard artist
- Evelyn Greenblatt Howren (1917–1998), American woman aviator and WASP
- Jack Greenblatt, Canadian scientist
- James Marshall (born 1967 as James David Greenblatt), American actor
- Jason Greenblatt (born 1967), American lawyer, United States Special Representative for International Negotiations
- Joel Greenblatt (born 1957), American financier
- Jonathan Greenblatt (born 1970), American entrepreneur and corporate executive
- Richard Greenblatt (born 1944), American computer programmer
- Richard Greenblatt (born 1953), Canadian actor/playwright
- Robert Greenblatt (born 1959/1960), American television executive and chairman of NBC Entertainment
- Rodney Alan Greenblat, American graphic artist
- Shon Greenblatt, American actor
- Stephen Greenblatt (born 1943), American new historicist literary critic and theorist