Foursome simply means a group of four people who're engaged in the same activity.
- Foursome (golf), a type of match in the sport of golf
- Foursome (group sex), group sex involving four people of any gender combination
- Foursome (TV series), an American adult reality dating series on Playboy TV
- Foursome of Nine Dragon Island, a set of four fictional characters featured within the famed ancient Chinese novel Investiture of the Gods
- Wild Things: Foursome the fourth film in the Wild Things franchise