Yokosuka, city and port in Japan, in Kanagawa Prefecture, on southern Honshu Island and Tokyo Bay, near the city of Tokyo. Yokosuka has a large, sheltered harbor. In the city, which is headquarters for a fleet of whaling ships, are automobile-assembly plants and shipyards. The development of Yokosuka dates from 1865, when a shipyard was established here. Population (1999) 432,889.
