Kōhoku-ku is one of the 18 wards of the city of Yokohama in Kanagawa Prefecture, Japan. As of March 1, 2012, the ward had an estimated population of 332,488, with 156,198 households and a population density of 10,588.79 persons per km². The total area was 31.40 km². Kōhoku Ward has the largest population of Yokohama's 18 wards, and ranks second to Naka Ward in the total number of workplaces.