Grillo is an Italian surname. Notable people with the surname include:
- Angelo Grillo, Italian poet and lyricist who wrote madrigals for Claudio Monteverdi
- Antonio Grillo (footballer, born 1986), Italian football defender
- Antonio Grillo (footballer, born 1991), Italian football defender
- Beppe Grillo, Italian comedian and politician
- Casey Grillo, American drummer
- Chuck Grillo, American professional ice hockey executive
- Elisabetta and Francesca Grillo, defendants in R v Grillo and Grillo
- Emiliano Grillo, Argentine professional golfer
- Ernesto Grillo, Argentine football player
- Frank Grillo, American actor
- Friedrich Grillo, German industrialist
- Gabriela Grillo (1952–2024), German equestrian and businesswoman
- Giovanni Battista Grillo, Venetian composer and organist (late 16th century–mid-November 1622)
- Janet Grillo, American filmmaker and screenwriter
- Leo Grillo, American film actor, producer and animal welfare activist
- Manuela Grillo, Italian sprinter
- Natasha Grillo, Italian professional racing cyclist
- Niccolò Grillo, Italian composer
- Odhise Grillo, Albanian writer of children's books
- Paride Grillo, Italian cyclist
- Roger Grillo, American ice hockey player and coach
- Santiago Grillo, Colombian windsurfer
- Tyran Grillo, Japanese writer and translator
- Yusuf Grillo, Nigerian painter
Fictional characters: