Bly or BLY may refer to:
Places
- Bly, Missouri, a ghost town
- Bly, Oregon, a small town in Oregon
- Bly, the fictional setting of The Turn of the Screw
Transport
- Belmullet Aerodrome in Ireland (IATA code BLY)
- Bletchley railway station in England (UK National Rail station code BLY)
- Burnley railway station in Victoria (Australian railway station code BLY)