The Nishiki River (錦川, Nishiki-gawa) is a 110 km long river, the longest in Yamaguchi Prefecture, Japan. The Nishiki is the main river in a larger system measuring 331.8 km in total. The government of Japan classifies it as a second-class river system. The Nishiki River system drains an area of 884.2 km². The Nishiki River has its source in the city of Shūnan. At its mouth in the part of the city of Iwakuni that was formerly the separate town of Nishiki, it drains into the Inland Sea.