There are two districts (amphoe) romanized as Bang Sai in the Phra Nakhon Si Ayutthaya Province, Thailand, differed only by the Thai spelling and the geocode
- Amphoe Bang Sai (1404) (บางไทร)
- Amphoe Bang Sai (1413) (บางซ้าย)
There are two districts (amphoe) romanized as Bang Sai in the Phra Nakhon Si Ayutthaya Province, Thailand, differed only by the Thai spelling and the geocode