Gren is both a given name and a surname. As a given name it is often used as a short name of Grenville or Grenfell. It may refer to
- Given name
- Gren (Grenfell Jones, 1934–2007), Welsh newspaper cartoonist
- Gren Alabaster (born 1933), New Zealand cricketer
- Grenville Goodwin (c. 1898–1951), Canadian politician
- Gren Jones (footballer) (1932–1991), English football player
- Gren Wells, American filmmaker, screenwriter, and actor
- Surname
- Axel Wenner-Gren (1881–1961), Swedish entrepreneur
- Friedrich Albrecht Carl Gren (1760–1798), German chemist
- Gunnar Gren (1920–1991), Swedish football player and coach
- Hans Gren (born 1957), Swedish football manager
- Linda Gren (born 1974), Swedish footballer
- Martin Gren (born 1962), Swedish entrepreneur and inventor
- Mats Gren (born 1963), Swedish football player and coach