A trio is a group of three identical or similar objects, or a grouping of three persons for a common purpose. (See tuple for alternative names.)
- Trio (music), three people performing music in some way
- Piano trio (piano, violin, cello)
- String trio (violin, viola, cello)
- Trio (jazz) (piano, double bass, drums)
- Clarinet-violin-piano trio
- Power trio (electric guitar, bass guitar, drum kit)
- Harmonica trio (chromatic harmonica, bass harmonica, chord harmonica)
- The middle section of a piece in ternary form
- The third section of a march (music)
- Trio (band), a German pop band who wrote "Da da da"
- The Trio, one incarnation of Trey Anastasio (band)
- Trio (album), a 1987 recording by Dolly Parton, Emmylou Harris and Linda Ronstadt. The group is also sometimes referred to as Trio.
- Trio II, a 1998 recording by Dolly Parton, Emmylou Harris and Linda Ronstadt
- The Trio, a live 1961 album featuring a jazz trio led by the Canadian jazz pianist Oscar Peterson
In other entertainment: