The Phachi River (Thai: แม่น้ำภาชี, RTGS: Maenam Phachi, Thai pronunciation: [mɛ̂ːnáːm pʰaː.tɕʰiː]) is a river in western Thailand. It originates in the Tenasserim Hills in Ban Kha district and passes Suan Phueng and Chom Bueng districts, Ratchaburi Province. The river tributes to the River Kwai in Mueang Kanchanaburi district, Kanchanaburi Province.