Uonuma (魚沼市, -shi) is a city located in Niigata Prefecture, Japan. It has an area of 946.93 km² and a population of 45,026 (as of March 31, 2004).
The city was established on November 1, 2004 in a merger of Horinouchi, Koide, Yunotani, Hirokami, Sumon and Irihirose.
