is one of the eight wards of Niigata City, Niigata Prefecture, in the Hokuriku region of Japan. , the ward had an estimated population of 161,884 in 68,119 households and a population density of 1700 persons per km<sup>2</sup>. The total area of the ward was .
Nishi-ku is located in a central Niigata city, bordered by the Sea of Japan to the north. The Shinano River flow through the ward.
The area of present-day Nishi-ku was part of ancient Echigo Province. The village of was founded on November 1, 1901, by the merger of five villages, and was raised to town status on February 1, 1973. It was annexed by Niigata city on January 1, 2001. The villages of , and were also established on November 1, 1901. Uchino was raised to town status on October 1, 1928, and was annexed by Niigata city on January 11, 1960. Niigata annexed Akatsuka and Nakanokoya on June 1, 1961. Niigata became a government-designated city on April 1, 2007, and was divided into wards, with the new Nishi Ward consisting of the former towns of Kurosaki and Uchino, and villages of Akatsuka and Nakanokoya.
Nishi-ku has eight public middle schools operated by the Niigata city government. The ward has three public high schools operated by the Niigata Prefectural Board of Education, one private high school and one private combined middle/high school.