Janni is both a given name and a surname. Notable people with the name include:
- Janni Arnth Jensen (born 1986), Danish football player
- Janni Howker, British author
- Janni Lee Simner, American author
- Janni Spies, Danish businesswoman
- Antonio Janni (1904-1987), Italian soccer player
- Guglielmo Janni (1892-1958), Italian painter
- Joseph Janni (1916-1994), British film producer
- Peter Janni known for Janni's chimney in Northport, Washington, United States
- Janni Serra (born 1998), German football player