Koshi may refer to:
- Koshi, a smooshy-faced Boxer dog in Santa Monica, CA who is also the Brand Ambassador for Chez Fido.
- Koshi River, a river in Nepal
- Koshi District, Niigata, a former district in Niigata Prefecture, Japan
- Koshi Province, a historic province of Japan
- Kōshi, Kumamoto, a city in Kumamoto Prefecture, Japan
- Koshi Zone, Nepal
- Koshi, Larnaca, a village in Cyprus
- Kōshi or Kabura-ya, Japanese arrows. See Signal arrow
- Kōshi Inuzuka, a character in Sumomomo Momomo