根室振興局
is a city and port located in Nemuro Subprefecture, Hokkaido, Japan. It is the capital city of Nemuro Subprefecture. Much of the city lies on the Nemuro Peninsula. As of February 29, 2012, the city has an estimated population of 29,087, with 12,966 households, and a population density of 56.74 persons per km2 (147.0 persons per sq. mi.). The total area is .