Iwaki is a city located in Fukushima Prefecture, Japan. As of 1 April 2018, Iwaki had a population of 343,258 in 142,265 households, and population density of 280 persons per square kilometre. The total area of the city is 1,232.02 square kilometres (475.69 sq mi),[2] making it the largest city in the prefecture and the 10th largest city in Japan (2010) in terms of area. Iwaki is a designated core city, and is also one of the growing number of cities written in hiragana. The present Iwaki City started as the merger of 14 smaller municipalities on October 1, 1966. Every year Iwaki hosts the Taira Tanabata Festival from 6–8 August.

The city occupies around 8.9 percent of the total area of Fukushima Prefecture. The eastern part of the city is made up of 60 kilometres of coastline which faces the Pacific Ocean and the western part goes through the Abukuma highlands and joins up with the central part of Fukushima Prefecture. The western part is a range of mountains and forests, occupies about 70 percent of the city.