Ichinomiya, city, northwestern Aichi ken (prefecture), central Honshu, Japan. The city lies on the Nōbi Plain about 20 miles (32 km) northwest of Nagoya.
It developed in the 7th century around the principal Shintō shrine of the locality, the Masumida Shrine. During the Edo (Tokugawa) period (1603–1867) it was an important transport centre on the Gifu Highway. Ichinomiya is now part of the Nagoya industrial area, specializing in woolen and cotton textiles for both kimonos and Western-style clothes. Pop. (2010) 378,566; (2015) 380,868.