Nyūzen(入善町,Nyūzen-machi) is a town located in Shimoniikawa District, in northeastern Toyama Prefecture, Japan.
With the Sea of Japan to the north, and Kurobe River to the west Nyūzen is located in the center of an alluvial fan. The town is famous for its jumbo watermelons, as well as its tulips which became the official town flower in 1983.