Kawanishi is a town located in Yamagata Prefecture, Japan. As of 1 January 2020, the town had an estimated population of 14,967 in 5052 households, and a population density of 90 persons per km². The total area of the town is 166.46 square kilometres (64 sq mi).

The Yonesaka Line is a railway line in Japan, operated by East Japan Railway Company. It connects Yonezawa Station in Yamagata Prefecture to Sakamachi Station in Niigata Prefecture. At Yonezawa, connections to the Yamagata Shinkansen and Ōu Main Line can be made; while the Uetsu Main Line connects at Sakamachi Station. The line takes its name from the first kanji of Yonezawa (米沢) and Sakamachi (坂町).