The Tha Chin river (Thai: แม่น้ำท่าจีน, RTGS: Maenam Tha Chin, pronounced [mɛ̂ːnáːm tʰâː tɕīːn]) is a distributary of the Chao Phraya river, in Thailand. It splits in the province of Chai Nat and then flows west from the Chao Phraya through the central plains, until it empties into the Gulf of Thailand in Samut Sakhon province.