Gratz is a surname. Notable people with the surname include:
- Alan Gratz, American author
- David E. Gratz, American engineer
- Dennis Gratz, Bosnian politician
- Dwayne Gratz, American football player
- Gusztáv Gratz, Hungarian politician
- Joan C. Gratz, American artist and filmmaker
- Karl Gratz, Austrian fighter pilot
- Leopold Gratz, Austrian politician
- Peter Aloys Gratz, German biblical scholar
- Rebecca Gratz, American educator and philanthropist