A pion is a type of subatomic particle.
Pion may also refer to:
- PION, gene; see Protein pigeon homolog
- 2S7 Pion, self-propelled gun
- Pión District, in Peru
- Posterior ischemic optic neuropathy
- Pio Pion (1887–1965), Italian entrepreneur
- Pion, Asturias, a parish in Villaviciosa, Asturias, Spain.